Based on the functional process of carbon sequestration of forest, we categorize carbon sequestration in two parts: carbon capture and carbon storage. Here, Pinus sylvestris var. mongolica was used to simulate the dynamic changing process of carbon sequestration of forest in a century using tree growth formula and the cost of carbon capture and sequestration. We found that the total carbon captured and stored by 100-year-old P. sylvestris var. mongolica are both 966 kg C tree^-1. On the assumption that the current year is the planting year, the present total carbon sequestration value (capital value) of 100-year-old P. sylvesrtis var. mongolica is 54.78 USD tree^-1 at the discount rate of 3%, with the present total carbon capture value of 18.92 USD tree^-1 and carbon storage value of 35.86 USD tree^-1. The dynamic process of the annual value of carbon capture is illustrated by an upside-down U shape curve, while that of carbon storage service follows an S shape curve. The combination of the dynamic processes of carbon capture value and carbon storage value represent the changing process of carbon sequestration value, which appears to be an S shape curve.