Abstract: The paper presented information of aboveground biomass dynamics of the Festuca extremiorientalis in the Taihang mountain grassland. The data indicate that the aboveground biomass was from 10.80 to 979.30gFW/m2 or from 5.00 to 351.33gDW/m2. The peak value of biomass varied was between 902.87 and 1092.15gFW/m2 or between 331.45 and 370.53gDW/m2.The biomass growth shows a uninodal form. The biomass peak value appear in July. This feature is in accordance with the climate of Taihang mountain characteried by distinct cold and hot seasons, and the corresponding time of hot and raing seasons. The biomass and growth peak shows an obviously positive correlation (R= 0. 8929). The biomass and coverage shows an positive correlation (R= 0.9066). The highest growth rate of biomass and growth high appear at same time. The highest relative growth rate of both appear 30-50 days ahead of their peaks In the growing season, precipitation was the main ecological factor of growth, and the regression equation of both shows y= 6. 2596 +l.4089x(R=0.9250).