Cloud computing is emerging approach because of high availability, efficient cost and performance. In Cloud computing, services providers will provide the storage for data along with services. But due the lack of proper security policies, many business companies are reluctant to adopt the Cloud computing technology. This paper has been written to highlight cloud security and privacy issues. The authors' research is mainly focus on service provider's side security. They must protect their client data by unauthorized access, modification or miss use, Denial of Services and repudiation.