Gas chromatography and high performance liquid chromatography（HPLC） were used to determine the residual degradation dynamics and final residues of 6 pesticides（profenofos， fenpropathrin， imidacloprid，acephate，acetamiprid，triadimefon） on chili in open field and greenhouse in North China. The result indicated that the original deposit amounts of 6 pesticides on pepper in greenhouse were 3.13，1.11，1.23，1.29，1.67 and 0.38 mg·kg^-1，respectively，which were 74.9%，3.7%，17.1%，27.7%，39.2% and 111.1% respectively higher than in open fields. In greenhouse，one day after spraying the residues were 3.78，1.27，1.88，1.36，2.85 mg·kg^-1 and 0.58 mg·kg^-1，which were 20.8%，14.4%，52.8%，5.4%，70.7% and 52.6% respectively higher than the original deposit amount in open fields. It turned out that the original deposit amounts of 6 pesticides（profenofos，fenpropathrin， imidacloprid，acephate，acetamiprid，triadimefon） on chili in greenhouse were remarkably higher than the corresponding values in open fields. The residues 1 day after were significantly increased than the original deposit amounts. Acetamiprid and triadimefon were safe on chili in greenhouse，while fenpropathrin was
unsafe. Profenofos，imidacloprid and acephate should be applied strictly according to the security recommended
dose.