Abstract：Taking 3-leaf stage Micro-Tom tomato seedlings as test material，this experiment assessed the damage extent of leaf blade by using RLA method after foliar spraying diff erent concentrations PPT or Kan solutions；classifi ed grading standard；determined the appropriate concentration for PPT or Kan screening；established a screening system for transgenic resistant seedlings；and conducted resistant screening verifi cation using T1 transgenic tomato seedlings with bar or nptⅡ．The results showed that the damages on Micro-Tom tomato seedlings by PPT and Kan all could be divided into 7 grades．When PPT concentration was 1.50-1.75 mg · L-1，Kan concentration was 120-150 mg · L-1，the response of tomato plants was obvious．Moreover，it would not cause irreversible damage and could be the suitable concentration for screening resistant seedlings of transgenic plants．The screening results of foliar PPT or Kan on T1 transgenic tomato seedlings were highly consistent with PCR clone verifi cation results using marker gene bar or nptⅡ．
