Abstract: The decomposition course of Castanopsis cuspidata leaf litter in the northern subtropical evergreen broadleaved forests,and the dynamics and diversity of soil fauna community of the Wuyi Mountains were studied by litter bag method.The results showed that the number of soil animal groups was relatively larger in the early stage of decomposition,and the number of medium and small sized soil animals in the fauna increased rapidly in the midstage.The diversity index of soil fauna was significantly and positively correlated with the group number of soil animals (r=074，P<005).Species in orders of Acarina and Collembola were the dominant animals in the soil fauna during the process of litter decomposition,and the number of soil animal individuals from these two orders accounted for 82.4%.The individual number of species in the order Collembola,and the suborders Oribatids and Mesostigmata of order Acarina,was all significantly positively correlated with the loss of litter mass examined.There was no significant relationship between the individual number of species in the orders Isopoda and Diptera and the loss of litter mass,Whereas,the individual numbers of species in the orders Eiymenopter,Araneae,Homoptera and Coleoptera were negatively correlated with the loss of litter mass.