[[abstract]]Hamilton (1989) proposed the regime-switching model to explain the different behaviors of mean and volatility for returns at different states of business cycle. However, the stock price has abnormal vibrations when the unanticipated information released via the stock indices and therefore leads into the regime-switching model with jump risks. According to empirical analysis in this paper, we find that 29 stock indices suitable for the regime-switching model with jump risks via LR test in the sample observations with 31 stock indices of the study period from 1999 to 2008 by expectation-maximization (EM) algorithm and supplemented expectation-maximization (SEM) algorithm. Also, both of the regime-switching model and the regime-swi...