Abstract: This study was mostly for Xishuangbanna tropical seasonal rainforests which disturbed by both deforestation and hunting.Some big tree dieback are due to trunk damaged.One apparent result of environmental change is that numbers of species and individuals of dirds are reduced dramatically.Many of these birds are trunk specialists which can forage pests in trunks,such as woodpeckers could have played a part in controlling trunk damaged.The progression of some tree dieback is associated with a progressive loss of birds both of species and individuals and trunk pests ramped.Many of big birds are suffering badly from hunting,however,the litte birds that mostly insectivorous are fortunate.A wide range of foliage insects are eaten by these birds,so that Xishuangbanna seasonal rainforests did not happen serious defoliation damage by insects.Levels of herbivory,judged from the proportion of areas of leaves in litterfall eaten by invertebrates was 16.4% which was as high as those in other tropical forests.Birds thus have the potential to influence insect population,and management to overcome tree dieback should provide habitat for birds,do not continually deforest,and we should pay more a attention to protect birds from hunting in Xishuangbann.