Providing video-on-demand streaming service to a large population of clients using peer-to-peer approach is drawing great interest recently. Since clients' demands are asynchronous and the buffered contents are continuously changing, how to find partners with expected data and collaborate with each other for future content delivery are very important and challenging. In this paper, we propose a generic buffer-assisted search (BAS) scheme to improve partner search efficiency. Extensive simulation results demonstrate that BAS can provide faster response time with less control cost than the existing search methods.