This study investigated the effects of different interplanting practices in Guangxi Eucalyptus plantations on litter decomposition. Through determining the optimum plantation management practices to optimise litter decomposition for maximising vegetation growth and soil quality, results from this study have the potential to provide the scientific grounds to improve Eucalyptus plantation operations. The results are as follows: The 360-day decomposition of the pure Eucalyptus plantation leaf and branch litter was 2.6 and 4.45% higher than that of the Eucalyptus + Elephant grass plantation, and 2.75 and 1.95% lower than that of the Eucalyptus + Mountain tephrosia plantation. The decomposition rate of the leaf litter was faster than that of branch litter in all the three forest stands types, and difference in decomposition rate between leaf and branch litter was 18.9, 17.05 and 19.7%, respectively, for Eucalyptus, Eucalyptus + Elephant grass and Eucalyptus + Mountain tephrosia plantations. The leaf litter decomposition rate in the Elephant grass and Mountain tephrosia plantation was relatively fast, with decomposition constants of 0.84 and 1.06, respectively, and the time for 50 and 95% decomposition the leaf litter was 0.62 and 3.36 a, and 0.43 and 2.60 a, respectively. Decomposition of leaf and branch litter in the Eucalyptus plantations had clear effects on litter nutrient levels. Nutrient immobilisation within leaf and branch litter ranged from 16.28 to 124.68% and nutrient release ranged from 4.22 to 22.21% among all interplanting practices. The litter P content dynamics differed from the other nutrients. The litter K, Ca, and Mg content declined with increasing decomposition time. With interplanting of Eucalyptus trees with herb age, facilitating Eucalyptus litter decomposition and its nutrient return to the soil. These beneficial interplanting effects on Eucalyptus plantations were greater for the Eucalyptus + Mountain tephrosia plantation than the Eucalyptus + Elephant grass plantation. This research will facilitate sustainable forestry development by improving our understanding of the effects of herbage interplanting methods on long-term production in Eucalyptus plantations. [ABSTRACT FROM AUTHOR]