The NO3 contents and organophosphorus pesticide residues in edible part of vegetables cultivated by a conventional or an organic farming methods were determined. The NO3 contents of vegetables cultivated by the organic farming method were between 120ppm and 4,523ppm, whereas its contents of vegetables cultivated by the conventional farming method were between 89ppm and 1,575ppm. Fifty two percent of vegetables cultivated by hte organic farming method accumulated NO3 content over than 2,000ppm, whereas 82% vegetables cultivated by the conventional farming method accumulated NO3 content below than 1,000ppm. The NO3 contents of lettuce dependent on the cultivation method obviously. The NO3 contents of lettuce cultivated by a hydroponic farming method were between 4,800 and 6,500ppm, whereas those cultivated by the conventional method were between 630 and 750ppm. The organophosphorus pesticide residues in edible part of vegetables cultivated by the conventional or the organic farming methods were not detected. The NO3 contents in edible part of vegetables cultivated by the organic farming method should be considered as one of several parameters to judge a real safe vegetable to be certified by goverment.