diff --git a/test/unionfind_test.cc b/test/unionfind_test.cc
new file mode 100644
--- /dev/null
+++ b/test/unionfind_test.cc
@@ -0,0 +1,104 @@
+/* -*- C++ -*-
+ *
+ * This file is a part of LEMON, a generic C++ optimization library
+ *
+ * Copyright (C) 2003-2008
+ * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
+ * (Egervary Research Group on Combinatorial Optimization, EGRES).
+ *
+ * Permission to use, modify and distribute this software is granted
+ * provided that this copyright notice appears in all copies. For
+ * precise terms see the accompanying LICENSE file.
+ *
+ * This software is provided "AS IS" with no warranty of any kind,
+ * express or implied, and with no claim as to its suitability for any
+ * purpose.
+ *
+ */
+
+#include <iostream>
+
+#include <lemon/list_graph.h>
+#include <lemon/maps.h>
+#include <lemon/unionfind.h>
+#include "test_tools.h"
+
+using namespace lemon;
+using namespace std;
+
+typedef UnionFindEnum<ListGraph::NodeMap<int> > UFE;
+
+int main() {
+  ListGraph g;
+  ListGraph::NodeMap<int> base(g);
+  UFE U(base);
+  vector<ListGraph::Node> n;
+  
+  for(int i=0;i<20;i++) n.push_back(g.addNode());
+
+  U.insert(n[1]);
+  U.insert(n[2]);
+
+  check(U.join(n[1],n[2]) != -1,"Test failed.");
+
+  U.insert(n[3]);
+  U.insert(n[4]);
+  U.insert(n[5]);
+  U.insert(n[6]);
+  U.insert(n[7]);
+
+
+  check(U.join(n[1],n[4]) != -1,"Test failed.");
+  check(U.join(n[2],n[4]) == -1,"Test failed.");
+  check(U.join(n[3],n[5]) != -1,"Test failed.");
+
+
+  U.insert(n[8],U.find(n[5]));
+
+
+  check(U.size(U.find(n[4])) == 3,"Test failed.");
+  check(U.size(U.find(n[5])) == 3,"Test failed.");
+  check(U.size(U.find(n[6])) == 1,"Test failed.");
+  check(U.size(U.find(n[2])) == 3,"Test failed.");
+
+
+  U.insert(n[9]);
+  U.insert(n[10],U.find(n[9]));
+
+
+  check(U.join(n[8],n[10]) != -1,"Test failed.");
+
+
+  check(U.size(U.find(n[4])) == 3,"Test failed.");
+  check(U.size(U.find(n[9])) == 5,"Test failed.");
+
+  check(U.size(U.find(n[8])) == 5,"Test failed.");
+
+  U.erase(n[9]);
+  U.erase(n[1]);
+
+  check(U.size(U.find(n[10])) == 4,"Test failed.");
+  check(U.size(U.find(n[2])) == 2,"Test failed.");
+
+  U.erase(n[6]);
+  U.split(U.find(n[8]));
+
+
+  check(U.size(U.find(n[4])) == 2,"Test failed.");
+  check(U.size(U.find(n[3])) == 1,"Test failed.");
+  check(U.size(U.find(n[2])) == 2,"Test failed.");
+
+
+  check(U.join(n[3],n[4]) != -1,"Test failed.");
+  check(U.join(n[2],n[4]) == -1,"Test failed.");
+
+
+  check(U.size(U.find(n[4])) == 3,"Test failed.");
+  check(U.size(U.find(n[3])) == 3,"Test failed.");
+  check(U.size(U.find(n[2])) == 3,"Test failed.");
+
+  U.eraseClass(U.find(n[4]));
+  U.eraseClass(U.find(n[7]));
+
+  return 0;
+}