Abstract: An effective test generation method for M×N CSA/CLA array multiplier with a 4 bits CLA chain as its final stage is presented in the paper. This method is independent of the size of multiplier and the concrete implementation of its basic cell. Compared with the previous work, the time for test is shortened and 28 test patterns are enough to ensure 100% fault coverage. Based on these patterns given,it is unnecessary to modify the structure of its basic cell as usual when building BIST circuit for such multiplier, so there is no degradation in the normal function of the multiplier.