diff --git a/src/App.jsx b/src/App.jsx
index 4a942e6..b12b4ee 100644
--- a/src/App.jsx
+++ b/src/App.jsx
@@ -171,17 +171,25 @@ function App() {
   const handleGlobalParsingConfigChange = useCallback((newConfig) => {
     setGlobalParsingConfig(newConfig);
 
-    // Sync parsing config to all files
-    setUploadedFiles(prev => prev.map(file => ({
-      ...file,
-      config: {
-        ...file.config,
-        metrics: newConfig.metrics.map(m => ({ ...m })),
-        useStepKeyword: newConfig.useStepKeyword,
-        stepKeyword: newConfig.stepKeyword
-      }
-    }))); 
-  }, []);
+    // Sync parsing config to files that still use the global metrics
+    setUploadedFiles(prev => prev.map(file => {
+      const fileConfig = file.config || {};
+      const usesGlobalMetrics = !fileConfig.metrics ||
+        JSON.stringify(fileConfig.metrics) === JSON.stringify(globalParsingConfig.metrics);
+
+      return {
+        ...file,
+        config: {
+          ...fileConfig,
+          ...(usesGlobalMetrics && {
+            metrics: newConfig.metrics.map(m => ({ ...m }))
+          }),
+          useStepKeyword: newConfig.useStepKeyword,
+          stepKeyword: newConfig.stepKeyword
+        }
+      };
+    }));
+  }, [globalParsingConfig]);
 
   // Reset configuration
   const handleResetConfig = useCallback(() => {
diff --git a/src/components/ChartContainer.jsx b/src/components/ChartContainer.jsx
index 8a6c5e3..c24e04d 100644
--- a/src/components/ChartContainer.jsx
+++ b/src/components/ChartContainer.jsx
@@ -260,12 +260,13 @@ export default function ChartContainer({
           return results;
         };
 
-        metrics.forEach(metric => {
+        metrics.forEach((metric, idx) => {
+          const fileMetric = file.config?.metrics?.[idx] || metric;
           let points = [];
-          if (metric.mode === 'keyword') {
-            points = extractByKeyword(lines, metric.keyword);
-          } else if (metric.regex) {
-            const reg = new RegExp(metric.regex);
+          if (fileMetric.mode === 'keyword') {
+            points = extractByKeyword(lines, fileMetric.keyword);
+          } else if (fileMetric.regex) {
+            const reg = new RegExp(fileMetric.regex);
             lines.forEach(line => {
               reg.lastIndex = 0;
               const m = reg.exec(line);
@@ -278,7 +279,20 @@ export default function ChartContainer({
               }
             });
           }
-          metricsData[metric.name || metric.keyword] = points;
+
+          let key = '';
+          if (metric.name && metric.name.trim()) {
+            key = metric.name.trim();
+          } else if (metric.keyword) {
+            key = metric.keyword.replace(/[:：]/g, '').trim();
+          } else if (metric.regex) {
+            const sanitized = metric.regex.replace(/[^a-zA-Z0-9_]/g, '').trim();
+            key = sanitized || `metric${idx + 1}`;
+          } else {
+            key = `metric${idx + 1}`;
+          }
+
+          metricsData[key] = points;
         });
 
       const range = file.config?.dataRange;
diff --git a/src/components/__tests__/ChartContainer.test.jsx b/src/components/__tests__/ChartContainer.test.jsx
index 378703a..04b1785 100644
--- a/src/components/__tests__/ChartContainer.test.jsx
+++ b/src/components/__tests__/ChartContainer.test.jsx
@@ -175,4 +175,38 @@ describe('ChartContainer', () => {
     opts.plugins.zoom.pan.onPanComplete({ chart: { scales: { x: { min: 0, max: 10 } } } });
     opts.plugins.zoom.zoom.onZoomComplete({ chart: { scales: { x: { min: 2, max: 4 } } } });
   });
+
+  it('uses per-file metric configuration when provided', () => {
+    const onXRangeChange = vi.fn();
+    const onMaxStepChange = vi.fn();
+    const files = [
+      { name: 'a.log', enabled: true, content: 'loss: 1\nloss: 2' },
+      {
+        name: 'b.log',
+        enabled: true,
+        content: 'train_loss: 3\ntrain_loss: 4',
+        config: { metrics: [{ mode: 'keyword', keyword: 'train_loss:' }] }
+      }
+    ];
+    const metrics = [{ name: 'loss', mode: 'keyword', keyword: 'loss:' }];
+
+    render(
+      <ChartContainer
+        files={files}
+        metrics={metrics}
+        compareMode="normal"
+        onXRangeChange={onXRangeChange}
+        onMaxStepChange={onMaxStepChange}
+      />
+    );
+
+    const mainChart = [...__lineProps].reverse().find(p =>
+      p.data.datasets && p.data.datasets.some(d => d.label === 'b')
+    );
+    const ds = mainChart.data.datasets.find(d => d.label === 'b');
+    expect(ds.data).toEqual([
+      { x: 0, y: 3 },
+      { x: 1, y: 4 }
+    ]);
+  });
 });
diff --git a/src/components/__tests__/GlobalConfigOverride.test.jsx b/src/components/__tests__/GlobalConfigOverride.test.jsx
new file mode 100644
index 0000000..1dafdb8
--- /dev/null
+++ b/src/components/__tests__/GlobalConfigOverride.test.jsx
@@ -0,0 +1,94 @@
+import React from 'react';
+import { render, screen, within, waitFor } from '@testing-library/react';
+import userEvent from '@testing-library/user-event';
+import { describe, it, expect, beforeEach, vi } from 'vitest';
+import '@testing-library/jest-dom/vitest';
+import App from '../../App.jsx';
+import i18n from '../../i18n';
+
+// Mock chart.js and react-chartjs-2 to avoid canvas requirements
+vi.mock('chart.js', () => {
+  const Chart = {
+    register: vi.fn(),
+    defaults: { plugins: { legend: { labels: { generateLabels: vi.fn(() => []) } } } }
+  };
+  return {
+    Chart,
+    ChartJS: Chart,
+    CategoryScale: {},
+    LinearScale: {},
+    PointElement: {},
+    LineElement: {},
+    Title: {},
+    Tooltip: {},
+    Legend: {},
+  };
+});
+
+vi.mock('react-chartjs-2', async () => {
+  const React = await import('react');
+  return {
+    Line: React.forwardRef(() => <div data-testid="line-chart" />)
+  };
+});
+
+vi.mock('chartjs-plugin-zoom', () => ({ default: {} }));
+
+function stubFileReader(result) {
+  class FileReaderMock {
+    constructor() {
+      this.onload = null;
+    }
+    readAsText() {
+      this.onload({ target: { result } });
+    }
+  }
+  global.FileReader = FileReaderMock;
+}
+
+describe('Global config override', () => {
+  beforeEach(() => {
+    localStorage.clear();
+  });
+
+  it('retains file metric config after global change', async () => {
+    stubFileReader('train_loss: 1');
+    const user = userEvent.setup();
+
+    render(<App />);
+
+    const input = screen.getByLabelText(i18n.t('fileUpload.aria'));
+    const file = new File(['train_loss: 1'], 'a.log', { type: 'text/plain' });
+    await user.upload(input, file);
+
+    await screen.findByText('a.log');
+
+    const configBtn = screen.getByLabelText(i18n.t('fileList.config', { name: 'a.log' }));
+    await user.click(configBtn);
+
+    const modal = screen.getByRole('dialog');
+    const keywordInputs = within(modal).getAllByPlaceholderText('keyword');
+    await user.clear(keywordInputs[0]);
+    await user.type(keywordInputs[0], 'train_loss:');
+
+    const saveBtn = screen.getByText(i18n.t('configModal.save'));
+    await user.click(saveBtn);
+
+    await waitFor(() => expect(screen.queryByRole('dialog')).not.toBeInTheDocument());
+
+    // Update global config
+    const globalKeyword = screen.getAllByPlaceholderText('keyword')[0];
+    await user.clear(globalKeyword);
+    await user.type(globalKeyword, 'val_loss:');
+    expect(globalKeyword.value).toBe('val_loss:');
+
+    // Reopen file config to verify keyword remains
+    const configBtn2 = screen.getByLabelText(i18n.t('fileList.config', { name: 'a.log' }));
+    await user.click(configBtn2);
+
+    const modal2 = screen.getByRole('dialog');
+    const updatedInputs = within(modal2).getAllByPlaceholderText('keyword');
+    expect(updatedInputs[0].value).toBe('train_loss:');
+  });
+});
+