With the typical conditions such as precipitation, temperature, soil type and wind as input parameters, the biomass dynamics and wind erosion in semiarid area of north China were simulated. Results show that biomass increases with the increase of precipitation and temperature, and wind erosion increases with the raise of wind velocity and the number of windy days. With the seasonal change of precipitation and temperature in semiarid region, biomass has the lowest value in early spring and the highest value in late summer, and wind erosion reaches the lowest in summer and the highest in early spring. There is an obvious interaction between biomass and wind erosion. In addition, biomass has the same spatial distribution trend with precipitation when the other parameters are fixed. Taking the change of temperature into consideration, the center of high biomass leans to where the temperature is higher. The change of terrain in small extent has little influence on the total value of biomass and wind erosion, but it changes the spatial distribution of them.