This paper proposes a new model for fault location about software compatibility testing based on combinatorial testing in order to lower cost, improve accuracy and simplify process during test. Based this model, this paper proposes a method to analyze fault location in compatibility testing. First of all, the model is built for softwares which need to do compatibility testing. After that, the tool Cascade is used to generate test cases for this model which are executed and get results. Finally, these test cases and execution results are input as the tool of Facil which is used for fault location about combinatorial testing. Facil will precisely find software set which causes the compatibility fault. Experiments show that the process of this method is simple and the result is effective and reliable. To some extent, it lowers cost, improves accuracy and simplifies process during test.
