Abstract: To elucidate the effects of soil NPK-fertilization on the relationship between host plant and sweet-potato whitefly (Bemisia tabaci), infestation and development of whitefly on potted cucumber plants under different fertilizer treatments were investigated. Results show that soil NPK-fertilization has significant effects on larval duration, survival rate of old nymphs and nymph size; non-significant effects on survival rate of whitefly egg and young nymphs. Adult whitefly prefers treated cucumber plants with medium concentration of nitrogen and without potassium and phosphorus, while it apparently avoids cucumber plants treated with high concentration of nitrogen along with potassium and phosphorus fertilizers. Whitefly longevity and fecundity are the shortest and the lowest on treated cucumber plants with only phosphorus fertilizer. In cucumber plants treated with high concentration of nitrogen along with potassium and phosphorus fertilizers, whitefly population increases 74.4 folds after one generation; while its population increases by only 17.2 folds in plants treated with phosphorus fertilizer only.