Abstract:The four rotations eucalyptus plantations with continuous planting were chosen in Hainan Island and forest structure characteristics and water holding capacity of soil and litter were investigated to examining the influence of continuous planting rotations on forest structure and hydrological regulating functions. The results show that the diameter at breast height (DBH), tree height and above ground tree biomass decreased with increasing continuous planting rotations and the declining trends of them stressed. The DBH, tree height and above ground tree biomass of the 4th rotation eucalyptus plantations were 43.4%、33.7%和42.7% lower than them of the 1st rotation plantations respectively. For forest biodiversity, the grass species under eucalyptus plantations decreased with increasing continuous planting rotations (p<005). For litterfall eco-hydrological roles, litter stock and maximum water holding capacity of the 1st rotations were higher above 30.0% than them of the 4th rotations. However, litter maximum water holding rate did not differed significantly among different continuous planting rotations (p>0.05). For soil eco-hydrology roles, soil bulk density increased and soil total porosity, final constant infiltration rate and water holding capacity obviously decreased as continuous planting rotations increased. There were significant differences in soil total porosity, infiltration rate and water holding capacity between the 1st rotation and the 3rd or 4th rotation. Thus, the continuous planting rotations clearly affected forest structural characteristics and eco-hydrological roles of eucalyptus plantations. Finally, the continuous planting rotations resulted in ecosystem services degradation of artificial eucalyptus forest.