[Objective] The aim of this study is to investigate the effects of ploughing area on soil and water loss, in order to provide basis for soil and water loss in Loess Plateau.[Methods] By artificial rainfall experiments, we studied runoff and sediment yield characteristics at three different slopes with different ploughing area.[Results] The runoff and sediment yield characteristics of cultivated land were not only related to the slope, rainfall intensity and soil moisture content, but also closely related to ploughing area. Under the same slope gradient, the initial runoff occurring time was delayed and the sediment yield was increased with the increase of ploughing area. Under the same ploughing area, runoff and sediment yield rate showed an increasing trend with the increase of slope gradient. And runoff reached to the maximum when the slope was 15ånd the ploughing area was 50%. Under the same gradient, the sediment yield showed an increasing trend with the increase of ploughing area. When the slope gradient was 10°, ploughing area had the greatest influence on sediment yield, and the average sediment yield of ploughing treatment was 8.66 times of no-till treatment. The runoff had the most significant influence on the cumulative sediment yield when the slope gradient was 15°. Runoff rate under different ploughing area became stable approximately 10 min after the initial runoff occurring. Under different slope gradient, sediment production rate of full-tillage was the largest in whole-ploughing, while the smallest in no-till.[Conclusion] With the increasing of ploughing area, the initial runoff occurring time is delayed, runoff decreased, and the sediment yield increased.