Abstract: Lodging is one of the constraints to the integrated production target of high yield, good quality, high efficiency for foxtail?millet (Setaria italica L.). In order to study the effect of Paclobutrazol on lodging resistance of foxtail?millet, ‘Jingu 21’ and ‘Zhangza 5’ were used as materials. The experiment was conducted as a randomized block design. Four concentrations (150, 300, 600, 1200 mg/L) of Paclobutrazol were applied on foxtail millet at the seedling stage, with distilled water as control. The culm mechanical strength and yield were determined at the harvest time. The?results showed that plant height, internode number and internode length decreased with increasing Paclobutrazol concentrations, whereas culm diameter, culm wall thickness and lodging resistance increased. Compared with the control, ‘Jingu 21’ and ‘Zhangza 5’ treated with 300 mg/L Paclobutrazol, plant height decreased by 14.12% and 22.10%, internode number decreased by 1.2 and 0.8, internode length of N3 decreased 1.70 and 2.20 cm , culm diameter increased 0.61 and 0.44 mm, culm wall thickness increased 0.64 mm and 0.29 mm, lodging resistance increased 24.79% and 47.55%, yield increased by 1.12 and 1.12 kg/hm2, respectively. In conclusion, treatment with Paclobutrazol 300mg/L at the seedling stage is benefit for forming the plant type with short and thick basal internodes, large wall thickness, culm plumpness status and strong lodging resistance, thus enhance yield.