Abstract: Evaluating the value of biodiversity conservation in state-owned forest farms can provide a basis for the performance management of these forest farms. Based on the study of the types of rare and endangered animals and plants as well as the ancient tree resources in Huading Forest Farm of Tiantai County, the value of biodiversity services of this forest farm is evaluated in accordance with the "Assessment Specification for the Service Functions of Forest Ecosystems". The results show that in Huading Forest Farm, there are 3 and 2 species of national first- and second-class protected wild animals, respectively, and 1 and 8 species of national first- and second-class protected wild plants, respectively. The forest farm is also rich in ancient tree resources, with 58 species and a total of 3757 ancient trees. Among them, 63 first-class protected ancient trees are ≥500 years old, accounting for 1.7%; 227 second-class protected ancient trees are 300–499 years old, accounting for 6.0%; and 3467 third-class protected ancient trees are 100–299 years old, accounting for 92.3%. The Shannon-Wiener diversity index of the forest in Huading Forest Farm is 11.4, and the index grade is Grade 1. The annual value of forest biodiversity conservation per unit area in Huading Forest Farm is 50,000 yuan per hectare, and the total value is 166.19 million yuan.