Group buying is one of the popular online shopping behaviors. However, most studies discussed it only from the viewpoints of price. This paper integrates the factors influencing online shopping behavior in group buying websites. The research results are shown as follows: (1) website quality and incentive mechanism have significant effects on the transaction cost; (2) website quality have significant effects on the incentive mechanism; (3) website quality and incentive mechanism have significant effects on the customer value; (4) customer value, trust and demand externality have significant effects on the purchasing intention.