The effects of simulated nitrogen (N) deposition on litter decomposition are of great significance for studying the inner mechanism of material cycle in forest ecosystem response to atmospheric N deposition and coping with the globalization of N deposition. From February 2018 to January 2019, a field experiment of simulated N deposition was conducted in two zonal vegetation (Evergreen broad-leaf forest and Quercus semecarpifolia forest) in central Yunnan province. The litterbag method was used for the litter (leaf and twig) in situ decomposition experiment in two forest types. Four treatment levels of N deposition were applied, i.e., control check(CK, 0 g N m^-2 a^-1), low nitrogen(LN, 5 g N m^-2 a^-1), medium nitrogen(MN, 15 g N m^-2 a^-1), and high nitrogen(HN, 30 g N m^-2 a^-1). The results indicated that the decomposition rates of leaf and twig in Evergreen broad-leaf forest were 44.84% and 21.96%, respectively, which were higher than 35.97% (leaf) and 17.51% (twig) of Quercus semecarpifolia forest. Under N deposition, the time of 95% mass loss (T_95%) of leaf and twig in two forest types increased to a certain extent based on the control, and the most significant one was in HN treatment. After one year's decomposition, the degradation of cellulose and lignin in leaf and twig litter were inhibited by N deposition. There was significantly positive correlation among litter mass remaining, cellulose and lignin remaining in two forest types. As for the two zonal vegetation in central Yunnan, the response direction of litter decomposition to N deposition mainly depended on the litter substrate, especially cellulose and lignin were important factors.