Abstract: In order to establish haifeng natural protection area in Zhanyi Yunnan Province, nature resources in this area should be surveyed.An investigation on the special underground forests has been conducted.The underground forests established in a special environment-some large natural hollows, and they have quite intact raw plant types protected by natural shields. The underground forests survive together in deep hollows, Covering a large area.Their ecological structures are different from those on the ground.The characteristics of the forest communities, including abundant plant species resources, special plant types, rare area systems of forest communities, great variation of ecological components, largely changeable ecological communities, great variation of ecological components, and intact forest structures are analyzed in detail.