[Objective] The influences of plants on reducing ditch erosion and C, N and P loss were studied in order to provide technical support for the prevention of ditch erosion and pollution control. [Methods] The study was conducted on ditches of the Nala River basin in the intensive sugarcane growing area of Southern Subtropical China. Vetiver (Vetiveria zizanioides, a herbaceous plant) was planted at different vegetation coverage amounts 〔bare ground. vegetation coverage of 0% (BG); somewhat covered, vegetation coverage of 1%—40% (SC); mostly covered, vegetation coverage of 41%—80% (MC); completely covered, vegetation coverage of 81%—100% (CC)〕 in the ditches. Regular field investigation and monitoring of planted ditches were conducted after rainfall events from April to October, and the characteristics of erosion and nutrient loss under different vegetation coverage were quantified. [Results] ① From April to October, the width, erosion amount, and nutrient loss of ditches with different vegetation coverage gradually increased over time. Values for all three parameters followed the same order of BG＞SC＞MC＞CC; ② Compared with BG, the erosion amounts for SC, MC, and CC decreased by 37.01%, 71.60% and 75.04%; C loss decreased by 35.56%, 70.91% and 75.23%; N loss decreased by 35.89%, 71.01% and 74.39%, and P loss decreased by 34.22%, 70.59% and 77.01%, respectively; ③ Correlation analysis showed that the erosion amount for ditches was significantly negatively correlated with vetiver grass coverage and plant root density (p＜0.01), accounting for 91.94% and 89.23% of the erosion changes, respectively. [Conclusion] As vegetation coverage increased, ditch erosion and nutrient loss gradually decreased. There were no significant differences in ditch erosion and nutrient loss when vegetation coverage was between MC and CC. These results provide guidance for ameliorating ditch erosion and reducing pollutants in other water source areas.