In order to evaluate the water conservation capacity of main forests in Xiaowutai Mountains and provide a new idea for the selection of water conservation tree species, the distribution characteristics and water conservation capacity of litter of seven typical forests in Xiaowutai Mountains were studied by immersion method and simulated rainfall method. The results showed that: (1) The litter thickness and distribution range of broad-leaved forests were greater than those of coniferous and broad-leaved mixed forests and coniferous forests, which were the greatest in pure forest of Populus cathayana Rehd. and pure forest of Quercus mongolica Fischer ex Ledebour, respectively, and the thickness on lower slope were greater than that on upper slope. (2) Litter accumulation followed the order of pure forest of Pinus tabuliformis Carrière > pure forest of P. cathayana Rehd. > mixed forest of P. tabuliformis Carrière and Q. mongolica Fischer ex Ledebour > pure forest of B. platyphylla Suk. > mixed forest of B. platyphylla Suk. and Picea asperata Masters > pure forest of Q. mongolica Fischer ex Ledebour > pure forest of Tiliatuan Szyszylowicz, and the litter accumulation of the semi-decomposed layer was larger than that of the undecomposed layer. (3) The litter holding capacity of the semi-decomposed layer was larger than that of the undecomposed layer, and the litter holding capacity of coniferous and broad-leaved mixed forests and mostly broad-leaved forests was greater than that of coniferous forests. Among them, the maximum water holding capacity, effective storage capacity and the final holding capacity of litter of pure forest P. cathayana Rehd. of were the greatest, which was 1.69, 1.37 and 0.41 mm, respectively. (4) The water holding capacity of litter in all forests was higher in immersion method than that in rainfall simulation method, so if only using the traditional soaking method, the results would be too large. The water conservation capacity of litter in broad-leaved forest, coniferous and broad-leaved mixed forest was better than that in coniferous forest, among which the water conservation capacity of pure forest of P. cathayana Rehd. and pure forest of B. platyphylla Suk. both were the strongest. More broad-leaved trees such as P. cathayana Rehd. and B. platyphylla Suk. should be selected in the selection of tree species for water conservation forest in the future.