Analysis of Cloud Computing Performance, Scalability, Availability, & Security Cloud Computing means that a relationship of many number of computers through a contact channel like internet. Through cloud computing we send, receive and store data on internet. Cloud Computing gives us an opportunity of parallel computing by using a large number of Virtual Machines. Now a days, Performance, scalability, availability and security may represent the big risks in cloud computing. In this paper we highlights the issues of security, availability and scalability issues and we will also identify that how we make our cloud computing based infrastructure more secure and more available. And we also highlight the elastic behavior of cloud computing. And some of characteristics which involved for gaining the high performance of cloud computing will also be discussed.