Abstract: Nowadays most research in software test generation has been focused on numeric data and string data.However,there are a few studies on test generation with respect to binary tree data structure,a widely used dynamic data structure.This paper proposes an automatic test generation approach for programs with binary tree structures.The shape of binary tree structure is created using genetic algorithm,and simultaneously the values in their data fields are generated by means of constraint solving.The experimental results show that the proposed method is promising and effective,and it is obviously superior to random test generation.