Abstract: Method of indoor soil dropping is used to study the safety of Tribenuron-methyl and Bensulfuron-methyl on different wheat strains and the change of the content of chlorophyll. It is showed that there exists big difference between the safeties of the two to different wheat strains and their inhibition to the length of root is greater than to the height of plant. Their impact to the content of chlorophyll is relative to their impact to the height of plant. Zhoumai 13 is sensitive to tribenuron-methyl and improper usage may cause damage. Yanshi 4110’s height of root is the safest to tribenuron-methyl and its height of plant is the most sensitive to it. Gaoyou 503’s length of root is the safest to bensulfuron-methyl and its height of plant is the most sensitive to it. Zhoumai 13’s height of plant is the safest to bensulfuron-methyl and its length of root is the most sensitive to it. Thus, proper herbicide, virtual dose and best method should be adopted according to the different wheat strain.