It is important to protect the structure, functions and process of nature ecosystem. This paper discussed the services valuation of forest ecosystem in nature reserves, which taking the Gudou Mountain Nature Reserve of Guangdong as an example. The methods applied in this paper included market-method, shadow-engineering method, product-cost method and substitute-expense method. Results showed that the total ecological value of this reserve was 57.887 615million Yuan. Among that, the production value was about 6.9 377 million Yuan; the production from the standing trees was about 4.05 million Yuan which was increased by tourism; the production from improving atmospheric environment was about 32.2 177 million Yuan; the production value from water holding and water cleaning was about 5.809 million Yuan and the value from soil conservation was about 8.878 215 million Yuan. The object of this study was to show the huge valuation of ecosystem services that provided by forest ecosystem of nature reserves and bring more attention from society to the valuation of ecosystem services, strengthen management and protection the forest ecosystem services.