ObjectiveTo study the characteristics of nonfunctioning parathyroid cysts (NFPTC) for its diagnosis and treatment.Methods 5 cases of NFPTC were hospitalized during 1985～1999. The clinical features, serum calcium evaluation ultrasonography and nuclide scanning were performed. Postoperative pathologic and immunihistochemistry detection in NFPTC were made.ResultsTumours in the 5 cases were removed by operation and diagnosis was verified by pathology. Tumors were all positive for chromogranin A (CgA),synaptophysin(Syn),and neuron specific enolase(NSE). Follow up found no recurrence. ConclusionsSurgical resection is most effective in treating NFPTC and diagnosis is made by pathologic examination.