Ｒelative to the wide application of online group buying in practice，there has been scant academic research． This paper is devoted to fill this gap by investigating the decisions on pricing and timing in online group buying market． Based on the degree of consumers’heterogeneity and time-sensitivity，we first subdivide the market and then examine the optimal strategies individually． Our results show that: 1) In the maximizing the seller’s revenue，pricing and timing decisions always exhibit some functional relationship． However，this relationship varies according to different market characteristics． 2) The principal of timing decision is to guarantee the purchase of every consumer in each segmented market． 3) Contrast to the unique optimal strategy in time-sensitive market，there have been two optimal strategies in the heterogeneous market，i． e． ，low pricing and high pricing． Which strategy should be adopted depends on the specific characteristics of the heterogeneous market． Finally，we conclude and present the selection process of the optimal strategy in the online group buying market．