Records of “3414” field trial for sweet potato during 2007 to 2010 were collected and analyzed for investigating the difference in soil fertility,establishing soil nutrient plentifullack index,and determining optimum fertilizer rate for sweet potato planting areas with different landforms of Chongqing.The results showed that the soil fertility in mountainous areas was higher than that in hilly regions.Based on the outcomes of the simulation model,the fertilizer recommended rates were obtained for sweet potato planting areas with different landforms.For hilly regions,the recommended N fertilizer rates were>137.4,109.35～137.4,81.3～109.35,53.1～81.3,<53.1 kg/hm2,when the soil available nitrogen content was<62,62～83,83～112,112～152,>152 mg/kg,respectively.The recommended P fertilizer rates were>64.2,50.25～64.2,<50.25 kg/hm2,when soil available phosphorus content was<6.3,6.3～16.7,>16.7 mg/kg,respectively.The recommended K fertilizer rates were>128.1,99～128.1,70.05～99,<70.05 kg/hm2,when soil available potassium content was<49,49～73,73～110,>110 mg/kg,respectively.For mountainous areas,the recommended N fertilizer rates were>162.15,123.75～162.15,85.2～123.75,<85.2 kg/hm2,when soil available nitrogen content was<55,55～82,82～122,>122 mg/kg,respectively.The recommended P fertilizer rates were>87.75,73.95～87.75,60.3～73.95,<60.3 kg/hm2,when soil available phosphorus content was<3.4,3.4～9.3,9.3～25.9,>25.9 mg/kg,respectively.The recommended K fertilizer rates were>151.5，126.3～151.5，101.1～126.3，75.9～101.1,<75.9 kg/hm2,when soil available potassium content was<53,53～77,77～114,114～169,>169 mg/kg,respectively.