Cost analysis :The cost of making diagnosis of CBD stone excluding all costs of treatment was analyzed. The cost of all patients with suspected CBD stones undergoing ERCP was calculated and compared with the strategy of EUS follow by ERCP. The cost was evaluated by (1) mean costs of EUS and ERCP based on the actual cost in our center which included costs of medical staffs, disposable materials, drugs, equipment amortization and maintenance. (2) cost associated with complications induced by the procedure.