By analyzing the soil and water loss monitoring observation data (2010-2016) of the Suining Soil and Water Conservation Experimental Station, this article studied the effects of Vetiveria zizanioides and Leucaena leucocephala hedgerows with different planting years which were layout in purple sloping farmland under natural rainfall conditions. The results showed that:(1) During the study period, when the hedgerows began to play its soil and water conservation role, the average annual runoff reduction rate reached 10.5%~20.0%, and the average annual sediment reduction rate reached 53.5%~54.5%. The reduction rates of hedgerows on average annual runoff fluctuated in different planting years, but its effect on reducing sediment gradually stabilized. (2) The Vetiveria zizanioides hedgerow (10°) showed the best influence on soil and water conservation, giving its reduction effects on runoff and sediment in its first planting year. Leucaena leucocephala hedgerows (10°) gave the inferior effectiveness on soil and water conservation, which sediment-reducing effect was one-year earlier than the runoff-reducing effect. The effects of Vetiveria zizanioides hedgerows (15°) were the worst, showing the lower runoff reduction rates than others. (3) In general, hedgerows could weaken the effects of slope gradients on soil and water loss on sloping farmland, in which runoff loss was decreased by 28.9%, sediment loss by 11.3%, and could also weaken the correlation between rainfall and runoff and sediment. (4) The runoff coefficient and sediment loss caused by the rainfall in hedgerow plots gradually stabilized with the increasing planting years. Torrential rain (12 hours precipitation over 140.0 mm) caused the highest runoff coefficient, followed by heavy rain (12 hours precipitation between 70~140 mm), the runoff coefficient caused by torrential rain and heavy rain were reduced by 15.0%~34.4% in the Vetiveria zizanioides hedgerow (10°) and Leucaena leucocephala hedgerow (10°) plots. The average sediment loss per millimeter of rainfall,was decreased by 34.1%~48.5% in hedgerow plots.