In terms of the importance of SRGM (Software Reliability Growth Model) in evaluating and ensuring reliability, in order to grasp the modeling and working mechanism of SRGM, the typical process of SRGM modeling and the differences of performance in different models are studied in this article. First, the fundamental assumptions and the meaning of SRGM modeling are illustrated, and the development of SRGM is summarized. Second, the modeling processes and the relationship of two basic types of SRGM are analyzed. For the tendency of considering more real testing factors into SRGM, the SRGM modeling process relative to the imperfect debugging and TE (Testing-Effort) are discussed. Finally, the performances of 8 typical models selected are compared using 4 published failure data sets, and analyses on the differences are illustrated. The results indicate that the objective differences in different failure data sets and subjective differences in cognition of testing process by different researchers are the main causes that account for the different performances of SRGMs. Further establishing a more accurate and comprehensive SRGM and selecting excellent ones on finite failure data sets are the problems that must be solved in the future.