Much attention has been attracted on the glacier meltwater due to its influence on the hydrological effect of glacial lakes through heat, water and material transmission in Mountain Cryosphere. We summarized the impacts of glacier meltwater on the hydrological effects with respects to the water quantity, physicochemical properties and biology of glacial lake in this paper. A certain amount of glacier water resources has been temporarily held resulted by the meltwater direct inflowing into glacial lakes, which retarded the loss water resources in the glaciated area to some extent on one hand, increased the number and hazardousness of the potential dangerous glacial lakes on the other hand. Glacier meltwater affects both physical and chemical properties of glacial lakes. Meltwater normally reduced lake temperature, disturbed lake transparency/turbidity, and facilitated thermal stratification of the glacial lake. Meltwater also increased the contents of nitrogen, dissolved organic matter, persistent organic pollutants, ion concentrations and heavy metals in the glacial lake water, influenced the distribution, composition, structure and function of glacial lake organisms and ecosystem. An in-depth and systematic research on the impacts of glacier meltwater and its changes on hydrological effect of glacial lakes, is of great significant to the glacier hydrology, water resources and ecological environment study of Mountain Cryosphere.