Abstarct: In the mountainous basins of the country, most of the rainfall was in the snow, which according to surveys, about 60% of surface water and 57% of underground water are in the snow-capped areas. They feed on melting water. In this study, the trend of snow cover changes in Lake Urmia with MOD10A2 images of MODIS sensor during the 18-year statistical period (2000-2017) was investigated. Also, data on total precipitation, minimum and maximum monthly temperature of meteorological stations in the lake of Urmia are analyzed and the correlation between these variables is determined by the level of snow cover. Finally, with the possession of data on the level of water in the lake, the trend of water level was studied and its correlation coefficient with variables was obtained. The results of this study showed that snow cover has a significant correlation with precipitation and temperature. In the winter and autumn rainfall and minimum temperatures, and in summer the maximum temperature is an important factor in snow accumulation and melting. Correlation coefficients were 0.385%, 0.5%, 5947.0%, and -0.567%, respectively, and in the summer of -0.623. But the level of water level contrary to expectation has a negative relationship with the total rainfall. This means that over the past 17 years, other factors such as harvesting of permanent and seasonal rivers that provide water for the lake, the construction of hydraulic structures, reducing the input of surface waters to the lake have had a greater impact on the lake water balance. Also, temperature has a significant relationship with the level of water level. In other words, with increasing maximum or minimum temperature, the level of water level in Lake Urmia decreases due to the evaporation of the lake.