Abstract: In order to increase the disease resistance of pepper, decrease the chemical pesticides usage, residue and environmental pollution, the methods of forecasting, randomized block design and statistical analysis were adopted to conduct field efficacy trials for testing the disease resistance of pepper by using plant immune inducer- amino-oligosaccharin. The results showed that after applying 750 and 1000 times liquid of 0.5% amino-oligosaccharin AS and 1000 times liquid of triacontanol (drug control) 3 days and 28 days after planting, and at young fruit stage, the antiviral effects were 97.6%, 69.0%, 76.2%; 94.1%, 63.5%, 72.9%; 87.0%, 63.9%, 72.2%; and 75.5%, 49.1%, 54.7%, respectively, on the 15^th, 30^th, 45^th and 60^th day after applying pesticide. The dark mildew control effects were 84.6%, 71.2%, 73.1%; 84.1%, 70.5%, 72.7%; 80.8%, 68.8%, 69.7%; and 72.2%, 53.7%, 55.6%, respectively, on the 15th, 30th, 45th and 60th day after applying pesticide. As well as the phytophthora blight control effects were all up to 100% after applying pesticide. These results manifested that the use of 0.5% amino-oligosaccharin AS could promote the nutrition growth and branch of pepper. Compared with that of the water control, the pepper yields of the treatments of 750 and 1000 times liquid of 0.5% amino-oligosaccharin AS and drug control were 30.2%, 13.3%, and 18.2% lower, respectively. And the sales revenues and net incomes were reduced by 21505.92, 9453.18, 12995.55 yuan and 21773.92, 9685.18, 13199.55 yuan. The yields of water control was significantly higher than that of the three treatments; the yields of 1000 times liquid of 0.5% amino-oligosaccharin AS and drug control was significantly higher than that of 750 times liquid of 0.5% amino-oligosaccharin AS; the yields of 1000 times liquid of 0.5% amino-oligosaccharin AS and that of drug control showed no difference.