OBJECTIVE: To investigate the diagnostic criteria and therapeutic method of the Klippel-Trenaunay syndrome. METHODS: Among 5 cases, there were 2 males and 3 females aged from 11 days to 73 years. Vasography was carried out in all five patients and MRA was performed in one patients. RESULTS: After operation, the symptoms improved in 4 cases: the portine-like erythemas on their limbs got unclear; the focuses diminished obviously; the circumferences of the suffered limbs shrank and the ulcer healed. For following-up period was not long enough, the long term therapeatic result was still uncertain. CONCLUSION: Once the diagnosis of the Klippel-Trenaunay syndrome was made, operation should be performed as early as possible. If the surgical time is selected in prepuberty, optimal result can be expected.