Abstract: To study the forest ecosystem service in different stages of forest transformation, Pinus massoniana forest was selected together with early, middle and late stages of transformed forest communities. The value of forest ecosystem services were evaluated according to the national standard of Specifications for assessment of forest ecosystem services in China (LY/T 1721-2008).The results showed that:(1) The unit value of forest ecosystem services were 76.5 thousand,75.1 thousand yuan,84.0 thousand yuan and 104.7 thousand yuan·hm^-2·a^-1,respectively in P. massoniana forest,sapling forest,mid-maturation forest and near-mature forest of C. camphora. (2) In the process of transforming P. massoniana forest into mixed forest of P.massoniana and C.camphora,forest ecosystem service was lower in early stage of forest transformation than that in P. massoniana forest because C.camphora was in the shrub layer.Then forest ecosystem services improved significantly as time went by.(3) In the process of P.massoniana forest management,mixed forests should be create and the operating period should be increased in sapling forest,mid-maturation forest in order to improve forest ecosystem service function.