Abstract: At present，O2O and B2C are the main patterns of medical e-commerce.And as a new pattern，O2O can promote precision marking and optimize allocation of resource by integrating online service and offline marking.The object of this paper is to compare B2C and O2O from consumer confidence，delivery efficiency，coverage and service and then make reasonable suggestions for pharmacy chains which is aim to develop e-commerce in term of the complementation between B2C and O2O.