diff --git a/string/kmp.py b/string/kmp.py
new file mode 100644
index 0000000..3f1c397
--- /dev/null
+++ b/string/kmp.py
@@ -0,0 +1,29 @@
+def kmp(s, t):  # find all occurrences of t in s
+    n = len(s)
+    m = len(t)
+    next = [-1]
+    j = -1
+    i = 0
+    while i < m:
+        if j == -1 or t[i] == t[j]:
+            i += 1
+            j += 1
+            if i != m and t[j] == t[i]:
+                next.append(next[j])
+            else:
+                next.append(j)
+        else:
+            j = next[j]
+    res = []
+    i = 0
+    j = 0
+    while i < n and j < m:
+        if j == -1 or s[i] == t[j]:
+            i += 1
+            j += 1
+            if j == m:
+                res.append(i - j)
+                j = next[j]
+        else:
+            j = next[j]
+    return res