Abstract: In order to promote the decomposition of Cunninghamia lanceolata litter, the study use net bag method to analyse the weightlessness rate, interspecific interaction and the relationship between decomposition rate and initial quality in litter diversity model which is based on C.lanceola litters. The results showed that after 1 year of decomposition, in addition to Schima superba-C.lanceola treatment and C.lanceola-Phoeba bournei treatment, the decomposition rate of other treatments were faster than pure litters of C.lanceola litter diversity treatments have mutually promoted effects on litter decomposition, especially on C.lanceolata-Michelia macclurei-P.bournei, C.lanceolata-M.macclurei-Manglietia yuyuanensis and C.lanceolata-M.yuyuanensis-P.bournei 3 groups of treatments, but litter diversity treatments have certain effect on the decomposition of C.lanceola litters, among which C.lanceolata-M.macclurei-P.bournei, C.lanceolata-M.macclurei-M.yuyuanensis, C.lanceolata-M.yuyuanensis-P.bournei and C.lanceolata-M.macclurei-M.yuyuanensis-P.bournei litter diversity treatments can promote the decomposition of C.lanceola litters more effectively while C.lanceolata-M.macclurei-M.yuyuanensis-P.bournei-S.superba litter diversity treatment inhibit the decomposition of C.lanceola litters. The correlation test indicated that decomposition rate of litters has very significantly positive correlation with initial cellulose content, the decomposition rate of litters has very significantly negative correlation with carbon content, lignin content, lignin/N and has negative correlation with C/N, C/K and lignin/K.