In this study, Characterization of the C, N, and P stoichiometry of the "plant-litter-soil" continuum was to guide the Pinus tabulaeformis forest productivity, and to understand the nutrient cycling and stability mechanisms of the forest ecosystem on the Loess Plateau. The P. tabulaeformis plantation grown for 10-, 25-, and 40-years in the Ziwuling area on the Loess Plateau was selected to determine the carbon (C), nitrogen (N) and phosphorus (P), as well as the stoichiometric characteristics in the leaves, litter, and soil during stand development. The results showed that the content of C, N, and P in leaves from the P. tabulaeformis plantations ranged from 538.85 to 560.54, 9.00 to 10.47, and 1.04 to 1.13 g/kg, respectively. Except for the C content in leaf, the N and P contents in the leaves were significantly different for the three stand ages (P < 0.05). The C, N and P contents in litter and soil were also significantly different for the three stand ages (P < 0.05), with litter having higher contents than soil. As the forest age increased, the leaf C:N ratios first decreased, and then increased; whereas the N:P and C:P ratios of the leaves were significantly increased. Meanwhile the C:N, C:P and N:P ratios of the litter did not significantly differ with the age of the P. tabulaeformis plantations. The contents of C and N in soil increased with increasing forest age, and were significantly higher (P < 0.05) at 0-10 depth than at the 10-20 cm depth in all plantation ages. However, the content of P changed litter in the soil profile. As the forest age increased, the soil C:P and N:P ratios at 0-10 and 10-20 cm depth and the soil C:N ratios at 0-10 cm depth increased, the soil C:N ratios at 10-20 cm depth decreased. For all plantation ages, the value of the N:P ratio in leaves was less than 14 under P. tabulaeformis plantations, which indicated that the growth of the plant in this study was limited by N. Correlations analysis showed that significantly positive correlations (P < 0.05) between the N content and N:P ratios existed for the leaves, litter, and soil, which indicated that content of N in the plant was affected by the supply of N in the soil. Overall, vegetation restoration improved soil quality in the Loess Plateau. The results can provide a scientific basis for the restoration of ecological function and vegetation in the fragile ecological region of the Loess Plateau in China.