In this paper we discuss the architecture characteristics of Multi-core and Multi-processor. According to this architecture, multithreaded algorithm is suitable. In order to make full use of Multi-core and Multi-processor, we must allocate threads to the appropriate core. So that multithreaded allocation algorithm is very important. In this paper we propose a multithreaded allocation algorithm based on Greedy algorithm. This algorithm allocates threads reasonably and makes the use of each core effectively.