The residue of imidacloprid in hulled rice and paddy soil was investigated. In laboratory conditions, the degradation of imidacloprid in the soils followed first-order reaction kinetic. The rate of degradation was influenced by soil temperature and soil type. The half-life of imidacloprid at $18-28^{circ}C$ was 66.7-96.3 days in the heavy clay soil and 56.8-117.5 days in the clay loam soil. Arrhenius activation energy obtained from the temperature experiment was 25.5 KJ/mol in heavy clay soil and 50.3 KJ/mol in clay loam soil. In paddy field, the degradation of imidacloprid was fast during the initial period but the degradation rate was gradually slow. About 10 % of the initial amount remained in the soil 120 day after the application. The residual amount of imidacloprid in rice was below the detection limit, 0.01 ppm. The residue level in rice was lower than MRL 0.05ppm in Korea.