Abstract: In the context of global warming, the influence of rainfall, temperature and sunshine hours on water environment in the Yilong Lake basin was studied. The results indicated that precipitation was positively correlated with COD and water temperature. There was a significant positive correlation between air temperature and water temperature, permanganate index, chemical oxygen demand, and chlorophyll A, however, the significant negative correlation with water quantity was found. The sunshine hours was negatively correlated with water temperature, chemical oxygen demand and water quantity. The analysis would provide scientific support for the lake protection.