Seasonal dynamics of soil microbial biomass C and N were measured under six vegetations restored for 10 years on degraded red soils.Vegetation increased soil microbial biomass(C and N) markedly in comparison with the eroded bare soil (CK).Soil microbial biomass expressed by seasonal means in 0~5cm soil layer differed significantly (p < 0.01) among vegetations, and they were decreased in the following order: protected grassland (G2) > slightly disturbed grassland (G1) > deciduous broadleaf woodland (Qc) > coniferous-broadleaved mixed woodland (Sm) > evergreen broadleaf woodland (Ss) > coniferous woodland (Pm).Compared with microbial biomass C, microbial biomass N was more sensit ive to the vegetations type.Soil microbial biomass showed a high degree of seasonality, and seasonal fluctuations were not consistent under different vegetations.ANOVA and Discriminant analysis indicated that vegetations had greater impact on soil microbial biomass than seasons.Stratification of microbial biomass was evident with sharply declined at lower depths.Changes of soil microbial biomass imposed by vegetations and sea-sons mainly happened in the surface layer of soil (0~5cm).Soil microbial biomass was significantly and positively correlated with soil organic matter and other biological properties, also it was capable of discrim-inating different vegetations distinctly.So soil microbial biomass had great potential as an indicator of red soil quality.Using soil microbial biomass to monitor the recovery of degraded red soil, soil sampling in spring was suitable and at least 0~10cm soil layer should be analyzed separately.Some possible high-lights in future study of red soil microbial biomass were also briefly given.