Grid computing is an upcoming technology which combines the resources from different locations to solve large tasks.Peer to peer (P2P) computing is a kind of computing in which large number of computers are connected through internet and their resources are utilized to solve large problems or tasks. It uses the idle cycles of all the computers connected to the network for solving huge parallel applications. An efficient scheduling mechanism is the most important challenge taken by the peer to peer network for utilizing the resources properly and also to assign the tasks to the resources effectively. Cooperation is very important because users in P2P networks tend to use the resources without providing any profit in response. In this paper, a comparative study has been done about several cooperative scheduling mechanisms that show their efficiency of improving the poor resource utilization and scalability.