Cloud computing is set of resources and services offered through the Internet. Cloud services are delivered from data centers located throughout the world. Cloud computing facilitates its consumers by providing virtual resources via internet. General example of cloud services is Google apps, provided by Google and Microsoft SharePoint. The rapid growth in field of "Cloud computing" also increases severe security concerns. This paper aims to identify security threats in cloud computing, which will enable both end users and vendors to know about the key security threats associated with cloud computing.