In todays era there is a vast demand of cloud computing because of the easy to maintain infrastructure with low cost. It is used in several areas including University, Hospital, E-Commerce and file storage services. This increasing demand of cloud computing is increasing day by day. As the peoples are growing in this platform also indicates the chances of malpractices and data theft. So this paper objective is to analyses the security threats which can be possible in cloud computing environment and suggest some effective steps to overcome. This paper also highlights the methodological reviews which are already done with their pros and cons.