diff --git a/src/com/blankj/medium/139 Word Break b/src/com/blankj/medium/139 Word Break
new file mode 100644
index 00000000..4db5785c
--- /dev/null
+++ b/src/com/blankj/medium/139 Word Break	
@@ -0,0 +1,19 @@
+	public boolean wordBreak(String s, List<String> wordDict) {
+		HashSet<String> words=new HashSet(wordDict);
+		int n=s.length();
+		boolean[] dp=new boolean[n+1];
+		
+		int len=0;
+		for(String word: wordDict) len=Math.max(len,word.length());
+		
+		dp[0]=true;
+		for(int i=0;i<n;i++){
+			if(!dp[i]) continue;
+			
+			for(int l=1;i+l<=n && l <= len ; l++){
+				if(words.contains(s.substring(i,i+l))) dp[i+1]=true;
+			}
+		}
+
+		return dp[n];
+    }