Abstract: According to analyzing the data on the mean monthlysea surface temperatures(SST for short) at grid points in the Northern Pacific,the relationships between SST field and yearly high-flow or low-flow in the upper Yellow River were revealed.The in fluence of abnormal changes of SST on the runoff was discussed.Meanwhile,theregression equation was established andthe data of SST was used to make longterm forecasting test on the yearly runoff in the upper Yellow River.The good effect was achieved.