Abstract: In this paper, using data of monthly mean geopotential height and SST in a statistic-relation analysis, the regularity and cause of long-term change of the latitudinal position of West Pacific subtropical high in early summer have been studied. The results indicate that there seems to have about 11-year and 3-5 year quasi-lleriods. The quasi-periodicity is closely associated with the changes in solar activity, SST in the eastern equatorial Pacific and the geopotential height in the upper troposphere in central and eastern tropical Pacific in Northern Hemisphere. The high's position tends to be more to the south of its normal location corresponding to peak years of sunspot and warm episodes of SST and positive phases of the geopotential height. Vice verse. According to the above conclusion, the forecast criterion of the ridge line of West Pacific Subtropical High for June has been found. Its foreeast results are satisfactory.