Abstract: To understand the temporal and spatial variation of soil microbial biomass P and its main controlling factors in subtropical forests regions in China, soil microbial biomass P and the associated factors were determined under different vegetations along an elevation gradients in the Wuyi Mountains National Nature Reserve, Fujian province, which were evergreen broadleaf forest (EBF, 500 m), coniferous forest (CF, 1 200 m), subalpine dwarf forest (SDF, 1 800 m) and alpine meadow (AM, 2 100 m) during April, 2006 to January, 2007. The results showed that: 1) Soil microbial biomass P content increased significantly with an increase altitude, which were 12.35 mg/kg, 14.63 mg/kg, 23.98 mg/kg and 31.99 mg/kg in 0—10 cm soil layer of EBF, CF, SDF and AM, respectively, soil microbial biomass P between different altitudes were significantly different except that no significant difference between EBF and CF (p <005); 2) Soil microbial biomass P was highest in top soil layer of 0—10 cm and decreased gradually with the increasing of soil depths; 3) there were consistent seasonal dynamics of soil microbial biomass P in four different ecosystems, which remained highest during winter, then tended to decrease during spring, and remained lowest during summer; 4) Correlation analysis of the data with 0—10 cm soil layer showed that soil moisture and soil organic matter content might be the main factors which controlling the spatial variations of soil microbial biomass P along the elevation gradients, and the seasonal variations of soil moisture and soil temperature mainly regulated the seasonal variations of soil microbial biomass P in subtropical forest regions of China.