Rapid development of technology has changed the way how consumers in Malaysia shop for products. Internet has become a common tool for both customers and business in purchasing and delivering goods and services. There is a tremendous growth between consumers in using internet to fulfill their shopping needs. The first characteristics of internet that has become the main reason that encouraged this phenomenon is, internet shopping has provided easy usage and conveniences to the customers.  Thus, it has become a particular way of shopping for the first generation that owned smartphones which is millennium. Not forgetting that in the year 2019, Malaysia government has frequently introducing the concepts of E-wallets to citizens of Malaysia. Thus, the adoption of E-wallets also played a part of its contribution in encouraging Malaysian to using online shopping and especially to generation y which are more technology savvy and having the behavior in trying new things. Even though m-commerce is expanding tremendously in Malaysia, and the discussion on consumer behavior is very being explore by scholars. But still there is lack of understanding of e- consumer behavior especially on China’s cosmetics. Thus, this research study is to determine the factors influencing purchase decision of generation Y female in Malaysia to purchase cosmetic products from China on WeChat and Instagram. The factors including independent variables which are brand awareness, E-word of mouth, service value and trust, dependent variable is the purchase decision of consumer. Also, the consumer’s purchasing intention as a mediating variable in effecting Generation Y female’s online purchasing decisions on China’s cosmetics is discussed.  This research is conducted among generation Y female in the Central cities of Malaysia and the Primary data collected is further analyzed using Statistical Package for Social Science (SPSS). By using descriptive analysis to look into the pattern of the data analyzed. Multiple regression analysis used to examine the relation between the independent variables, dependent variables and mediating variables. The analysis on the relationship between variables shown that they do affect the purchase decision of china cosmetic towards generation Y on WeChat and Instagram in the central cities of Malaysia.