Forest fire plays a vital role in the succession of forest ecosystems, and determines species composition, structure stability and species diversity in the forest ecosystems. In this study, we investigated the understory vegetation of Larix gmelinii-Betula platyphylla forests in Daxing’anling Mountains, and analyzed the recovery process of burned areas with the method of spatial pattern instead of time series. The results showed that the community composition changed from xerophytes to mesophytes and hygrophytes in the shrub and herb layers, while species diversity did not show an increasing trend with the community succession. In the herb layer, species richness index showed an increasing trend at beginning and then decreased after 5-8 years on the burned areas. Similarly, species diversity index reached the maximum value 5 years after the fire and tended to be relatively stable value 20 years after. Species evenness index reached its lowest value about 5 years after the fire, then presented an increase and then tended to be stable finally. The temporal trend of species diversity index in the shrub layer was similar to that of herbaceous species but there was a lag of 3-5 years. Understory biomass increased exponentially with restoration age, reaching 10.5 t·hm^-2 at 25 years after the fire.