Abstract: Shimai15 is a water-saving and high yield new line, in order to know the effect of growth inhibitor on declining the length of stalk & preventing lodging and yield of wheat of shimai15 and others, experiment was done in spring by using PP333 and CCC. The result showed that growth inhibitor affected the stalk growth, declining the length of internode, but the earlier spraying time influenced the length of base internode obviously, the latter spraying time had more effects on the top stalk. The dry weight of stalk was reduced with applying of growth inhibitors and the translation of deposited matters from stalk to seed was promoted, which raised yield and show the effect of concentration gradient obviously. The experiment definituded the best application dosage of two growth inhibitors was 2250g昲m2(CCC), 450g昲m2(PP333) and the solution 450kg/hm2.