Abstract: The media background of e-market,problems of information transparency and media richness are analyzed.The e-market coordination strategies and supply chain contract strategies are analyzed.As the main trend of B2B e-market,the buyer centric B2B e-markets are analyzed with emphasis,especially the problems of supply chain coordination,including returns contract,forward and spot contract.Furthermore,operation,coordination and optimization problems of the seller centric and third party centric B2B e-markets are also analyzed.Finally,several problems needed to be studied further are put forward,including the proportion and scale of B2B operation,double marginalization and bullwhip effect,supply chain contracts,capital and financial strategies,and coordination under the information sharing environment.