Abstract: Plant litter decomposition is one of the most important processes in nutrients cycling of forest ecosystem. Soil fauna plays an important role in this process. Many physical and chemical methods could be used to study the effects of soil fauna on litter decomposition in forests. Methods were discussed in this paper, such as litterbags, elimination with chemistry,electropnration, and mathematical modeling. Each method is incomplete. Litterbags can be used to study the impact of different kiuds of soil fauna on the litter decomposition, but the mesh sizes of the bags can not exclude the soil fauna entirely. Although elimination with chemistry, has a relatively better exclusion ability to the soil fauna, some kinds of chemicals may aher the microbe activity and lead lower estimation of the impact of soil fauna on the litter decmnpositioo. Electroporation is the best way to reduce the earthworm, but it is unfit to other species. Mathematical modeling can not estimate the litter decomposition rates accurately. With the development of the study, some studies on the quantity and appraisal of the soil fauna have also been made. As all of them are incomplete, they need to be further developed in some aspects in order to get more delicate relationship between soil fauna and the decomposition.