This paper described the measurement results of the dissolved oxygen(DO) in the water bodies of seventeen lakes over Hengduan Mountains. The average DO content in the lakes is about 5.86 mg/L to 8.35 mg/L, and the maximum value is 14.54 mg/L. The distribution of DO content is varying with different lakes at different altitudes and the value decreases with the increasing of elevation. Because of the water movement, the DO content in the upper part of lake water is nearly stable. But in deep lakes, the DO content is obviously different between upper part and lower part, and the value decreases with the increasing of the water depth, for example, in the Mahu Lake there is no oxygen beneath the depth of 100 m, so no living creatures exist. Through the themocline about 10 m to 50 m beneath the water surface in some lakes, DO content decreases sharply. In addition, the DO content distribution in some lakes is also affected by aquatic plant growth and organic pollution.