The research objective: To study the methods used to modeling constraints and improve constraint solving capability. To apply symbolic execution technique in automatic test case generating. To implement proposed methods in automatic test case generating on string constraints and mixed constraints. To analyze and evaluate the obtained results.

This thesis aims to research on overview of automatic test case generating, symbolic execution applied into automatic test case generating. The modeling techniques based on Automata and Bitvector are also studied in this thesis. Apart from that, the analysis and evaluation of available test case generating methods on different constraint are mentioned. The quality and effectiveness of test cases generated by using symbolic execution are assessed.