Litter is an important component of forest ecosystems, and its production and substrate quality influence the cycling of nutrients among plants and the soil. Therefore, to explore the relationships among litter production, litter chemistry, and meteorologic factors, three Pinus massoniana stands with different stand densities (low, medium, and high) were selected and compared on a monthly basis. The production of leaf litter exhibited a bimodal distribution pattern, with a smaller peak in February and a higher peak during October and November. The concentration of N and P varied considerably among months (P < 0.05), with peak values observed from April to June and significantly lower values observed from August to December. The concentration of lignin (L) varied considerably among months (P < 0.05), with the highest concentration observed in February and subsequent decreases until July or August. The C/N, C/P, L/N, and L/P ratios also varied between months (P < 0.05), with significantly lower value in April, May, and June and significantly higher values in September, November, and December. The ranges spanned nearly two-fold or three-fold differences, and all were above critical values, which generally inhibits the release of N and P. Meanwhile, stand density significantly influenced litter quantity and N concentration (P < 0.05), with significantly more litter produced by the medium-density stand and a significantly lower N concentration in litter from the low-density stand. The substrate quality of the litter were closely related to litter quality and were influenced by temperature and precipitation, whereas monthly litter production was negatively correlated with the litter's N and P concentrations and positively correlated with its C/N, C/P, L/N, and L/P ratios. Therefore, greater litter production was associated with lower litter quality and, subsequently, slower decomposition.