In recent year, the growth of embedded software is seen as the key factors of information technology industry to improve their hardware product competitiveness. However, embedded software are often closely related with hardware and OS, makes embedded software difficult to understand with the general software because of lack of structured programming. Derivation of test cases is not easy systematic or test coverage is insufficient, and can not to promote the quality and reliability of embedded software. In this research, we proposed a test model to support analysis and test of embedded software based on C programming language. This test model is to capture the information of the hardware and OS interface interaction with embedded software, for example: read/write and initial register or allocate memory etc., and annotate thesis information in the program’s call graph and control flow diagram, to help developer analysis the structural of embedded software and interaction with hardware and OS. Through this test model, we divided software’s execution path into (1)hardware-dependent interface; (2)OS-dependent interface; and (3)application interface. Derivation of test case by the interface parameter and property of the hardware an OS, to verify the structure of embedded software and different test coverage criteria. In addition, we have developed an embedded software structural analysis and testing tool. This tool can analyze embedded software program and automatically construct the proposed test model to assist the writing test case and testing conducted in order to enhance the quality and reliability of the embedded software.