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 +1,114 @@
+/* -*- 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/maps.h>
+#include <lemon/unionfind.h>
+#include "test_tools.h"
+
+using namespace lemon;
+using namespace std;
+
+typedef UnionFindEnum<StdMap<int, int> > UFE;
+
+void print(UFE const &ufe) {
+  cout << "Print the classes of the structure:" << endl;
+  int i = 1;
+  for (UFE::ClassIt cit(ufe); cit != INVALID; ++cit) {
+    cout << "  " << i << " (" << cit << "):" << flush;
+    for (UFE::ItemIt iit(ufe, cit); iit != INVALID; ++iit) {
+      cout << " " << iit << flush;
+    }
+    cout << endl;
+    i++;
+  }
+  cout << "done" << endl;
+}
+
+
+int main() {
+  StdMap<int, int> base;
+  UFE U(base);
+
+  U.insert(1);
+  U.insert(2);
+
+  check(U.join(1,2) != -1,"Test failed.");
+
+  U.insert(3);
+  U.insert(4);
+  U.insert(5);
+  U.insert(6);
+  U.insert(7);
+
+
+  check(U.join(1,4) != -1,"Test failed.");
+  check(U.join(2,4) == -1,"Test failed.");
+  check(U.join(3,5) != -1,"Test failed.");
+
+
+  U.insert(8,U.find(5));
+
+
+  check(U.size(U.find(4)) == 3,"Test failed.");
+  check(U.size(U.find(5)) == 3,"Test failed.");
+  check(U.size(U.find(6)) == 1,"Test failed.");
+  check(U.size(U.find(2)) == 3,"Test failed.");
+
+
+  U.insert(9);
+  U.insert(10,U.find(9));
+
+
+  check(U.join(8,10) != -1,"Test failed.");
+
+
+  check(U.size(U.find(4)) == 3,"Test failed.");
+  check(U.size(U.find(9)) == 5,"Test failed.");
+
+  check(U.size(U.find(8)) == 5,"Test failed.");
+
+  U.erase(9);
+  U.erase(1);
+
+  check(U.size(U.find(10)) == 4,"Test failed.");
+  check(U.size(U.find(2)) == 2,"Test failed.");
+
+  U.erase(6);
+  U.split(U.find(8));
+
+
+  check(U.size(U.find(4)) == 2,"Test failed.");
+  check(U.size(U.find(3)) == 1,"Test failed.");
+  check(U.size(U.find(2)) == 2,"Test failed.");
+
+
+  check(U.join(3,4) != -1,"Test failed.");
+  check(U.join(2,4) == -1,"Test failed.");
+
+
+  check(U.size(U.find(4)) == 3,"Test failed.");
+  check(U.size(U.find(3)) == 3,"Test failed.");
+  check(U.size(U.find(2)) == 3,"Test failed.");
+
+  U.eraseClass(U.find(4));
+  U.eraseClass(U.find(7));
+
+  return 0;
+}