Abstract: The matrices multiplication is often used in NWP. On distributed systems, such as IBM-SP, the multiplication of two matrices requires data transpose and the efficient data communication are crucial to its performance. Two parallel algorithms are presented, one is based on column-row decomposition and another is based on mesh partition, and the implementation and communication-time of this two different methods are discussed. Results on IBM-SP show that the communication in mesh algorithm are less and the improvement on speedup is up to 10%.