[Objective] In order to provide a theoretical basis for the restoration and protection of soil resources, we explore the composition and stability of different forest soil aggregrates in Fengyang Mountain Nature Reserve.[Methods] This study determinated soil aggregates particle size distribution and the content of different forms of Fe and Al oxides in different soil layers(0-10 cm, 10-20 cm, 20-30 cm), and analyzed the effects of various forms of Fe and Al oxides on the stability of soil aggregates in four main forest types(broad-leaved mixed forest, coniferous and broad-leaved mixed forest, Chinese fir forest, bamboo forest)during 1 300~1 400 m of Fengyang Mountain Nature Reserve, Zhejiang Province.[Results] ① The content of soil water-stable macroaggregates(WSA)(>0.25 mm) in four forest types were above 90%, and the order of the content of water-stable aggregates and mean weight diameter(MWD) of soil aggregate were fir forest > coniferous and broad-leaved mixed forest > broad-leaved mixed forest > bamboo forest. ② The order of Fe and Al oxides contents in different forms is Free Fe(Fe_d) > Free Al(Al_d) > Amorphous Fe(Fe_o) > Amorphous Al(Al_o) > Complexing Fe(Fe_p) > Complexing Al(Al_p) ③ The result of boosted regression tree(BRT) analysis showed that soil aggregate MWD was mainly influenced by Al_p in various forms of Fe and Al oxides, which produced a 43.6% contribution rate, followed by Al_d(23.5%) and the Fe_d(19.5%); Fe_o(6.9%), Al_o(4%) and Fe_p(2.4%) had less effect.[Conclusion] Al_p, Al_d and Fe_d can promote the stability of soil aggregates. The effect of complexed alumina Al_p on the stability of soil aggregates is greater than that of free Fe and Al oxides Al_d and Fe_d.