Abstract: The spatial pattern and seasonal dynamics of the aboveground and belowground biomass in Artemisia ordosica communities were studied at Ordos Sandy Grassland Improving Experimental Station of the Grassland Research Institute, the Chinese Academy of Agricultural Sciences, in 1991. The results showed that the aboveground biomass of the Artemisia ordosica community varied with community types, with the shifting sandland having the lowest biomass, while the semi-shifting sandland the highest. The aboveground biomass of a single dominant Artemisia ordosica community showed apparent seasonal dynamics, with a peak occurring in the middle of September or later. Thick roots accounted for the highest portion of belowground biomass in the Artemisia ordosica community, and the majority of the roots was concentrated in the upper layer (0—20cm) of the soil. The vertical distribution of belowground biomass can be described by exponential equations, showing clearly the trend of decreasing belowground biomass as a function of increasing soil depth.