Abstract: To determine the label use of acetamiprid in cucumber and soil, field experiments were compared in open fields and greenhouse conditions. Acetamiprid residues in cucumber and soil were extracted with acetonitrile, cleaned up with solid phase extraction (SPE). All samples were analyzed by high performance liquid chromatography. Sprayed once with high dosage of 30.375 a.i g/hm2, the initial residue concentrations of acetamiprid in cucumber and soil treatment were 0.20, 0.13 mg/kg in open fields, and 0.29, 0.14 mg/kg in greenhouse. The half-life of acetamiprid is 9.7 d in cucumber and 9.4 d in soil in open field, and 10.1 d/11.9 d in greenhouse conditions for cucumber/soil, respectively. Two days after applied one or two times with 20.25 or 30.375 a.i g/hm2, the residue of acetamiprid in harvested cucumber ranged from 0.01 to 0.05 mg/kg in open field, and ranged from 0.01 to 0.09 mg/kg in greenhouse. It's found that final residues in cucumber in open fields were generally lower than that in greenhouse under same application conditions.