Taking 6 varieties of radish as experimental material, effects of Abscisic Acid（ABA）, Cmoreholinchlorid（CCC）, and Uniconazole（S₃₃₀₇） on bolting were studied. In this experiment, 3 growth regulators were sprayed on radish seedlings at trefoil stage. The results showed that the C/N, budding rate, and bolting rate decreased by application of exogenous growth regulators. The effects of S₃₃₀₇ 600 mg·L^-1 was the most obvious for decreasing bolting rate of radish among three plant growth regulator treatments. The responding of different radish varieties to growth regulators was different in bolting. The treatment of S₃₃₀₇ decreased the C/N in leaf of radish ‘Weiqing No.3’,‘Qiaotouqing’,‘Shuiluobu No.501’ and ‘Mantanghong’to 54.2%,37.14%, 34.62%, 62.20%, respectively. The inhibiting of budding rate and bolting rate were significantly.