Cloud computing is bringing a revolution in computing environment replacing traditional software installations, licensing issues into complete on-demand services through internet. Microsoft office 365 a cloud based office application is available to clients online hence no need to buy and install the software. On Facebook a social networking website, users upload videos which use cloud providers storage service so less hardware cost for clients. Virtualization technology has great contribution in advent of cloud computing. Paper describes implementation of Private Cloud using open source operating system Ubuntu 10.04 server edition, installation of Ubuntu Enterprise Cloud with Eucalyptus 1.6.2 and providing CentOS 5.3 operating system through cloud.