diff --git a/src/MultiSet.java b/src/MultiSet.java
new file mode 100644
index 0000000..7f681ce
--- /dev/null
+++ b/src/MultiSet.java
@@ -0,0 +1,14 @@
+public interface MultiSet {
+    /*An abstract class representing the MultiSet ADT, which supports the
+    add, remove, is_empty, count, and contains operations.
+
+    This class itself does not handle how the underlying data is stored,
+    so it just inherits Object.__init__.*/
+
+    public boolean add(Object item);
+    public void remove(Object item);
+    public boolean contains(Object item);
+    public boolean is_empty();
+    public int count(Object item);
+    public int size();
+}