To study the influence of contour reverse-slope terrace on runoff and sediment production, nitrogen and phosphorus loss in sloping farmland, the loss of runoff, sediment, nitrogen and phosphorus of sloping farmland were monitored from 2009 to 2015 through conducting the standard runoff plots in a typical Yizhe small watershed in Water Source Area of Songhua Dam in Kunming City. The results showed that the reduction effect of contour reverse-slope terrace on runoff and sediment was significant, the annual average reduction rate of runoff was 50.64% and the annual average reduction rate of sediment was 74.99%, the latter was significantly greater than the former. The reduction effect of contour reverse-slope terrace on nitrogen, phosphorus in runoff and sediment was significant, it reduced 68.75% of nitrogen loss and 82.16% of phosphorus loss every year, the annual reduction rates of total nitrogen in runoff and in sediment were 59.51% and 76.43% respectively, and the values for total phosphorus were 64.22% and 83.73%, respectively.