Abstract-Electronic commerce, frequently known as e-commerce, has explored a new world before the vendors and customers, created a bigger virtual marketplace. With the widespread use of Internet, the online business and commercial transactions have reached to an extraordinary height, almost covering more than half of the world. Another rapidly emerging technology, cloud, is one of the most popular choices for the IT industry today. Due to its versatility, storage optimization capacity, performance, 24 x 7 service availability cloud has created its great impact in the ground of E Commerce. The present era is "cloud" era of E Commerce. But cloud, due to its distributive nature, incurs some extra baggage to the E Commerce security issues. This paper focuses on various security issues in Cloud based E Commerce. The main focus will be on cloud based E Commerce services especially for B2B and B2C E Commerce.