Online group purchase has become a promising impetus in the era of electronic commerce, which is featured by a large number of group purchase websites. In this paper , based on the Expectation Confirmation Model (ECM) with some adjustment，some group purchase websites are selected as the research object and the structural equation model is introduced in the empirical analysis of the theory and assumptions. The factors of the consumers’ continual use intention after initial use is studied and the model is verified. The research model consists of seven factors including perceived usefulness, perceived economy, perceived enjoyment, trust, satisfaction, conformation and continual use intention. Nine assumptions are also presented in this paper. The result shows that the consistency between consumers’ expectation and user experience greatly influence perceived usefulness, perceived economy and satisfaction, which in turn, imposes significant impacts on the customers’ continual use intention, yet factors like trust has no significant effect on the continual use intention.