Abstract: This paper presents the parallel algorithm experimental results on numerical weather prediction, which have been carried out by using the dual CPU computer system consisting of three IBM 4381-P03 installed at SMC/SMA, Beijing, According to the x-and y-coordinate directive decomposion (fork)-composion (join), the IBM 4381-P03 dual CPU have executed the calculation of the model difference scheme which is conditionally stable in form but nonconditionally stable in fact. The preliminary experiment results show: (1) IBM 4381-P03 with dual CPU can excite parallel algorithm in a common separate task way. (2) MVS grand operating system controls the Multitasking Facility (MTF) in the VS FORTRAN library to execute the decomposing task—parallel processing—waiting synchronization, to carry out the parallel algorithm. It is the first time to calculate NWP model in parallel way in China. From now on, we may execute step by step the parallel algorithm on the NWP and on the satellite informations processing. (3) In our estimation, a speed-up ratio of the parallel programming for the initial value problem is about 1.3 to 1.5, but not reaches the 1.8 level of the IBM yet. So it is worth to further exploit potentialities of the dual CPU