Abstract: Field survey, immersion test and simulated rainfall experiments were engaged in a preliminary study to clarify the hydrological effects of litter layers under rubber plantations in Xishuangbanna, southwestern China. Results showed that the litter reserves of the 20 and 40 years’ rubber plantations were 8.896 t／hm2 and 6.181 t／hm2, the proportions of the litter amount of their components (foliage, twig, seed and nutshell, others) were 57.1 ％, 10.2 ％, 32.2 ％, 0.4 ％ and 70.4 ％, 13.7 ％, 15.4 ％, 0.5 ％, respectively. The maximum water capacity of litter of the 20 years rubber plantation was 180.36 ％ of its dry weight, which of the 40 years’ was 174.59 ％. The equation between the water absorption rate of the litter and the immersed time could be S=ktn, and the first two hours was critical for litter to hold water. Under the condition of simulated rainfall, the interception rainfall increases with rainfall intensity and litter thickness. The interception rate existed a significant power function relation to rainfall, but it was hardly influenced by rainfall intensity. Interception rate of litter at the rainfall of 8.0—48.0 mm varied from 2.02 ％—12.50 ％. Based on these results, the hydrological effects of litter layers under rubber plantations were discussed so that it can provide some useful recommendations for operating them reasonably.