Abstract: By the methods of sequential soil cores and buried bags,  an investigation was conducted to study the seasonal dynamics of fine roots in a 20-year-old Pinus massoniana plantation in Three Gorges Reservoir Area from March to December 2011, with the annual production and turnover rate of the fine roots calculated. In the plantation, the annual mean biomass of <2 mm fine roots was 146.98 g·m^-2·a^-1, in which, the living root biomass (102.92 g·m^-2·a^-1) was far greater than that of the dead root biomass (44.06 g·m^-2·a^-1). Among the fine roots with different sizes, <1 mm fine roots had an obvious seasonal dynamics in their biomass, showing a unimodal curve in the sampling period. The annual production and turnover rate of <2 mm fine roots were 104.12 g·m^-2·a^-1 and 1.05 a^-1, respectively, in which, the annual production of <1 mm and 1-2 mm fine roots was 58.35 and 45.77 g·m^-2·a^-1, and the turnover rate was 1.41  and 0.69 a^-1, respectively. 