Litter decomposition is a crucial ecological process that regulates nutrient cycling. How ever, the effects of understory plants and overstory trees on litter decomposition andnutrient dynamics are still poorly understood. We conducted understory plants removaland/or overstory trees removal to examine the resulting effects on litter decompositionand nutrient mineralization in two Eucalyptus plantations with contrasting ages (8-yr-old,29-yr-old) in subtropical China. Litter bags containing naturally senesced leaves of eitheroverstory Eucalyptus urophylla or understory Dicranopteris dichotoma were placed in fifieldand periodically collected for analyses of carbon (C), nitrogen (N), phosphorus (P) andcalculation of mass loss. Our results showed that understory plants removal signifificantlyreduced litter decomposition of E. urophylla in both plantations, but N and P mineralizationwere reduced only in the 8-yr-old plantation. In contrast, it reduced litter decomposition ofD. dichotoma only in the 29-yr-old plantation, but had no effects on N and P mineralizationin either plantation. In comparison, overstory tree removal did not have any effects ondecomposition or mineralization of N and P of E. urophylla and D. dichotoma litters. Theseresults indicate that the role of understory plants in mediating litter decomposition andnutrient mineralization is more important than overstory trees, and it can be altered bystand age and plant species. Our fifindings could facilitate the understanding of ecologicalprocesses of litter decomposition and nutrient mineralization in subtropical forestecosystems.