Cloud computing has become a part of everyone's life now. So researchers have immense interest in cloud performance and security. For security and to provide single system image so that user gets an illusion that everything is stored at his own system cloud uses concept of virtualization. For that different virtual machines (VMs) runs on same or different servers. These VMs can be migrated from one server to another. VM migration and power consumption on cloud has been a trending area of research. In this paper a survey in done on VM migration techniques with keeping power consumption in mind. So in this paper green algorithm for VM migration are discussed.