This paper proposes an automated testing method of China UnionPay business of commercial banks based on TTCN-3.The method takes the core business system of commercial banks as system under test (SUT), chooses China Union Pay business transaction to interact with SUT. According to the method, we developed the universal TTCN-3 test system, including universal TTCN-3 extract test suite and adapter platform. The test system has many advantages. First, it can be applied by all the commercial banks, which join in the information exchange network of China UnionPay Bank Card. Secondly, it can execute test cases automatically and generate test report...