Yinma River is an important tributary of middle and upper reaches of Songhua River, with Yitong Riveras the tributary. In order to gain the characteristics of erosion and the load of non-point source pollution in riverside farmlands around downstream of Yitong River（within Nong’an Area）, the related research was conducted betweenApril and October, 2015, in which the field contents of pH value, organic substance, available nitrogen and avail-able phosphorus were measured in each of successive months in the 10 sample collection points set on both sides of the mainstream of Yitong River basin and its tributary Xinkai River, the central arterial drainage and Erdaogou,through the methodology of field trial in combination of general USLE. Besides, the erosion amount and nitrogen and phosphorus pollution output load were also estimated subsequently. The results showed that in 2015, soil contents of organic substance, available nitrogen and available phosphorus were（11.05±8.08）-（21.14±22.81）g/kg,（119.812±53.955）-（205±161.287）mg/kg and（9.78±5.88）-（33.03±24.99）mg/kg. During summer and autumn（April-October）,the three above-mentioned indexes and the soil pH value demonstrated a distinct U-shaped variation trend with average erosion intensity value of 3.2982 t/ha. The soil erosion intensity value was 2.48 t/ha in July, taking up 75.19%of the whole year, whose intensity and variation trends were depended on the rainfall distribution within the year.The overall loads of available nitrogen, available phosphorus in field non-point pollution were 214.985 kg/ha and 10.219 kg/ha, respectively, among which, the solid available nitrogen and available phosphorus were 102.57 kg/ha and 112.415 kg/ha and the dissolved ones were 0.14 kg/ha and 10.079 kg/ha, separately. The amounts of the dissolved nitrogen and phosphorus were 1.1 and 72 times that of suspending ones, thus becoming the main output of non-source point. In addition, the solid organic substance output was 102.092 kg/ha.