The message passing system is crucialto the computational performance of workstation clusters．With the fast growth in the performance of networking device，the unnecessary overhead in traditionalTCP／IPprotocolhas become the bottleneck of communication speed．To fully exploitthe communication potentialofthefast hardware，this paper introduces FMP，a new communication protocol specifically designed for Myrinet． FMP，which consists of a network part and a localpart，is a concise protocol．The physicallayer is assumed tobe error free and thus the protocolbecomes extremely simple and highly efficient．Compared with TCP／IP，theperformance ofFMPis much better．In this article the essentialtechniques used in the protocolare discussed andsome results are presented．