Abstract: Selecting environmental agents to control potato comm on scab, is the best measure of saving cost and increasing benefit in potato production. Potato root-irrigating was treated with four environmental agents-matrine, dictamnine,abenzionthiazolinone and xinjunan in potato piece formation, to control potato common scab. Through to analysis the control efficacy of various environmental agents, the experiments results indicated that the control efficacy of two times root-irrigating with matrine was 53%, and the control efficacy of two times root-irrigating with dictamnine was 80%t, and the control efficacy of two times root-irrigating with benziothiazolinone was 81%, and the control efficacy of two times root-irrigating with xinjunan was 94%. The control effects of four agents by root-irrigating two times were better than one time, the results of variance analysis of 9 treatments showed that the control efficacy of two times root-irrigating with xinjunan is better.