Abstract: Abstract：This paper built an impact model of information richness on consumer’s purchase decision in peripheral route under the framework of ELM model. Taking a quasi-commodity product, i.e., Kingston 32G USB flash drive, as sample and collecting the real transaction data from Taobao, it made an empirical analysis of the relationship between information richness and purchase decision. The results show that the seller’s reputation information richness, the review pieces and screenshot of buyer’s review information richness and the certified product guarantee of SSF information richness have positive influence on both consumer’s purchase intention and purchase behavior while the promotional information richness only influences the purchase intention. In addition, the good’s detailed information richness, the review score of buyer’s review information richness and other SSF information richness have no significant influence on consumer’s purchase intention or purchase behavior. Research conclusions provide the network third-party platform and sellers with a way of changing potential consumer to real consumer through peripheral route.