In this paper, the market valuation method, shadow engineering method, opportunity cost method and substitute expense method are used to value the functions of the forest ecosystem in Baiyun Mountain. The valuation results reveal that the total ecological value is estimated up to 145.80 million yuan per annum, of which, about 14.24 million yuan is of the output of standing trees, about 4.61 million yuan of water conservancy and soil conservation, about 36.24 million yuan of carbon fixation and oxygen production, about 6.32 million yuan of the animals' habitat and biodiversity protection, 17.37 million yuan of hygiene, about 1.34 million yuan of nutrient retention for N, P and K, about 0.17 million yuan of SO₂ degradation and control of diseases and pests, about 23.39 million yuan of the increase of grain output, and about 42.14 million yuan of tourism.