The correlation analysis is carried out based on the meteorological and hydrological data available(1959-1988).The results show that the main meteorological factors affecting the Qinghai Lake water level are the previous yearns precipitation, annual evaporation, vapor pressure saturation difference and ice thawing temperature especially in May.Those factors come in the following order (together with their phases) according to their contribution to the Qinghai Lake water level: (1) the previous year's rainfall (positive),(2) the annual evaporation (negative),(3) vapor pressure saturation difference (negative), and (4) mean temperature in May (positive).The meteorological factors to influence the waters around Qinghai Lake differ with the distance from their origins.The water flow of those shorter and more distantly originated rivers (for example, the Shaliu River) is directly determined by the newly arrived rainfall; the water flow of those longer rivers (such as Buha River) which originate in the icy and snowy mountaineous regions is determined by the on-the-spot heat conditions of the origins and solid water reserve of the catchment.