Base on the surface mass accumulation data in year of 1987/88, both distribution and variability of annual mass balance on Mizuho Plateau have been discussed. The authors also studied how they were influenced by means of shortterm climatic and topographical variations. It is found that there are some big differences between the year of 1987/88 and other years. In the region below 550 m a.s.l. which is near the coast, the mass balance appeared as negative. For the distance of 80 km from S16 to inland the annual net mass balance was 0.84 m snow depth. From 80 km point to Mizuho Station, it is considered as low mass balance zone with only 0.14 m snow depth. In Mizuho Pla-.teau, the level of massbalance appears to be as low accumulation and low expenditure. The influences of shortterm climatic and topographical variations to the mass balance were more heavy in this year than in other years. In the high accumulation zone, the influence of the shortterm climatical variation is greater than that of topographical one, while in the low value zone, the latter is greater than the former.