The geographical position, lake basin shape, features of watershed system, and natural general conditions about Mahu Lake are detailed in this paper.For the sake of water resources study, the authors surveyed the lake topography, analyzed the volume balance of lake water, observed the water colour, transparency, water temperature, dissoluble gas, pH value, xnacronutrient, mineralization, and water type, etc.in Mahu Lake.According to the water resources characteristic of Mahu Lake, the anthors attach the importance to its exploitation and utilization.