Abstract: To find out the growth characteristics and the difference of yield and quality of different varieties and different seedling generations of sweet potato, the tube seedlings, original- original seedlings, original seedlings, common seedlings of virus- free sweet potato of‘Yizi- 138’and‘Jingshu- 6’were used as materials, and the virus detection, yield- increasing effect assessment, quality test and cost- effectiveness analysis were conducted. The results showed that the incidence of sweet potato virus reduced after detoxification. The lower the generations, the fewer the diseased plants and virus types were. After detoxification, the number of the seedlings of the sweet potatoes increased in the seedbed, the seedlings were strong and the vegetative growth of the aboveground part was vigorous. The potato number underground and commodity potato rate increased in the field. However detoxification had less effect on the inner quality of sweet potato. In terms of the yield and cost-effectiveness, the yield of‘Yizi-138’original seedlings was 26288.4 kg/hm2, which had obviously significant yield-increasing effect (increased by 52.1%) compared with the control, and the increasing income was 13288.95 yuan/hm2. The yield of‘Jingshu-6’original seedlings was 11381.1 kg/hm2, which had obviously significant yield-increasing effect (increased by 53.3%) compared with the control, and the increasing income was 2045.1 yuan/hm2. In conclusion, it is recommended to use ‘Yizi-138’as the major variety to demonstrate and popularize the detoxification technology because it shows outstanding yield and income increasing effect.