[Objective] To study the carbon storage of natural Pinus tabulaeformis in order to provide theoretical basis for the management of carbon fixation and storage management in natural P. tabulaeformis forest in Songshan Mountain in Beijing City.[Methods] We set up standard plots in natural P. tabulaeformis forest, and sampled biomass of trees, shrubs, grasses and litter, and then collected soil samples at a depth of 0 to 100 cm. The correlative models were used to estimate the carbon storage of natural P. tabulaeformis forest ecosystem and different components.[Results] The vegetation carbon content changed from 42.39% to 49.95%, and it changed from 0.26% to 1.31% in the soil layer from 0 to 100 cm. The average carbon storage of P. tabulaeformis ecosystem was 147.24 Mg/hm², and the average carbon storage in vegetation was 57.14 Mg/hm², accounted for 36.7% of ecosystem carbon, carbon storage in each layer of the forest were trees(54.93 Mg/hm²) > shrub(0.45 Mg/hm²⁾ > herb(0.29 Mg/hm²). The average soil carbon storage was 66.35 Mg/hm², accounting for 46.30% of ecosystem carbon and 1.16 times the vegetation and 2.79 times litter carbon storage. The soil carbon content decreases with the increase of soil depth. Litter average carbon storage was 23.75 Mg/hm², accounting for 17% of ecosystem carbon storage.[Conclusion] Natural forest in Songshan mountain area contributed most to vegetation carbon storage, and carbon content of natural P. tabulaeformis forest in Songshan mountain area vegetation follows an order of arbor > shrub > herb > litter.