Cloud Computing is a relatively new computing approach which promises enhanced scalability, flexibility and cost-efficiency. In practice, however, there are many uncertainties about the usage of this way of provisioning IT resources. Concerns about evolving dependencies and security issues have arisen. As online commerce is dependent on reliable, secure online stores, it is vital to take those concerns into account. Users of cloud computing systems always concern about their private data. Securing the cloud is a multidisciplinary challenge, as cloud computing can be thought of as a different way to deliver and use all of the same types of information technology people use today. Thus making user to trust in cloud computing is the great challenge of adopting cloud computing. Nowadays most of E-commerce web sites intend to use cloud computing facilities to increase their functionality and their customer’s attraction. So identifying the factors that influence E-commerce customer’s trust on cloudy E-commerce facilities is critical for the new type of businesses.