[Objective] The decomposition characteristics and influencing factors of plant litter for ecological restoration of a coal mining subsidence area were analyzed in order to provide a theoretical basis for restoration in an arid climate. [Methods] An one-year decomposition experiment that included three litter treatments (Salix psammophila; Populus simonii; 1∶5 ratio of S. psammophila∶P. simonii) and two decomposition soils (sandy soil, loess soil) was conducted in a coal mining subsidence area of Inner Mongolia using the field decomposition bag method. The residual dry mass and contents of organic carbon (OC), nitrogen (N), phosphorus (P), acid detergent fiber (ADF), and acid detergent lignin (ADL) of litter samples were determined once every two months. [Results] ① The decomposition rate of S. psammophila litter was significantly (p＜0.05) greater than the decomposition rates of P. simonii and the mixed treatment by 10%~15%. The litter decomposition rates in the loess area were significantly greater than in the sandy area by 13%~23%. ② The litter source had significant (p＜0.01) effects on OC, N, and P contents. Soil type had significant (p＜0.05 or p＜0.01) effects on OC, N, P, ADF, and ADL contents. Both tree species and soil type were important factors affecting the nutrient transformations of the litters. ③ The OC and N contents of S. psammophila litter were greater than those of P. simonii and the mixed litter. P content of P. simonii and the mixed litter were lower than the P content of S. psammophila litter during the first four months, and then the P contents of all of the treatments were similar. [Conclusion] P. simonii litter decomposed more slowly than S. psammophila litter, and therefore, can be maintained for a longer time on the surface of soil. Therefore, P. simonii is recommended to be used as a suitable restoration plant in the coal mining subsidence area of Inner Mongolia.