Abstract: In order to explore ecological benefits of public welfare forest, promote government and society investing continually on it, and ensure development to management of public welfare forest, the anthor applies shadow engineering method, equal-effect substitute method, cost analysis method and market substitute method to evaluate the value of ecological benefits of Guangxi public welfare forest, to make value of ecological benefits of public welfare forest quantitatively. The valuation result shows that main ecological benefits value of Guangxi public welfare forest is estimated up to about 137. 39 billion RMB annually, among which, 69.25 billion for value of conserving water resources, 15.72 billion for value of soil conservation and soil fertility, 46. 53 billion for value of carbon sequestration and oxygen generation, 4.81 billion for value of cleaning environment, 1.08 billion for value of forest tourism. Totally, Value of ecological benefits of Guangxi public welfare forest is expected to 11.3 times as its economic value, which only 12.15 billion. That also means ecological value is far larger than economic value.