Litter decomposition is a key process of nutrient cycling in terrestrial ecosystems and a major component of the global carbon budget, which is presently being affected by the global atmospheric nitrogen deposition. Studying the litter decomposition and nutrient release patterns might be of great importance for better understanding the carbon balance and nutrient cycling of forest ecosystems in response to global change. Many studies on the litter composition have focused on fallen leaves. However, very little is known about the composition of fallen branches and fruits. To investigate the response of nutrient (C, N, and P) dynamics in fallen leaves, branches, and fruits decomposition to elevated N deposition, a field experiment was conducted in a Chinese fir (Cunninghamia lanceolata) plantation, located at the Guanzhuang National Forestry Farm, in the subtropical region of China. Simulated N deposition treatments were designed as N0 (0 kg hm^-2 a^-1, control), N1 (60 kg hm^-2 a^-1, low-N), N2 (120 kg hm^-2 a^-1, medium-N), and N3 (240 kg hm^-2 a^-1, high-N), with three replicates in each treatment. Starting from January 2004, each treatment was sprayed with CO(NH₂)₂ on the forest floor at the beginning of each month, and this spraying is being continued till date. After 12 years of N-application, the decomposition of fallen leaves, branches, and fruits were studied by using the litterbag method. The fresh litter samples were collected in December 2015 and sorted into three litter fractions:leaves, branches, and fruits from each plot. Decomposing litter in the litterbags was collected at 3-month intervals for 2 years from each plot, and then the mass loss and C, N, and P contents were determined. The results showed that the percentage of dry matter remaining of fallen leaves, branches, and fruits was on an average 27.68%, 47.02%, and 43.18%, respectively, for all the treatments, after 2 years of decomposition. The decomposition rate of litterfall fraction decreased in the order leaf > fruit > branch. The decomposition coefficients (K values) of fallen leaves, branches, and fruits were 0.588, 0.389, and 0.455 on average. The turnover period (time to 95% decomposition) of litter leaves, branches, and fruits was 4-5 years, 6-8 years, and 5-7 years, respectively. Low-and medium-N treatments (N1 and N2) had a significant, positive effect on the litter decomposition rate, with N1 showing a greater impact. The turnover period (time to 95% decomposition) was 4.50, 6.09, and 5.85 years for fallen leaf, branch, and fruit, respectively, under N1 treatment, and 4.95, 8.16, and 6.19 years, respectively, under N2. Simulated N deposition increased the N and P contents in the litterfall fractions, but decreased the C content. During the decomposition process, litter C showed release-enrichment-release pattern, and N and P showed alternately release and enrichment patterns, except for the N content in the branches. The released amounts of litter C, N, and P content were greater than the enrichment. In summary, low-and medium-N deposition promote litter decomposition, with stronger effects for the low-N treatment. The litter C, N, and P exhibited the pattern of nutrient release under long-term N deposition.