Abstract:In order to understand the dynamic pattern of endogenous hormones in leaves of the main stem of winter wheat varieties sowed in spring. A field experiment of two sowing dates(Ⅰ: early sowing; Ⅱ; normal sowing) was carried out at Xinding basin with 2 winter wheat cultivars imported from the middle and lower reaches of the Yangtze river region in China, Yangmai 13 and Yumai 10. Those varieties were sowed in spring in Xinding basin area of Shanxi province. The results showed that dynamic changes in endogenous hormones in leaves of the main stem of winter wheat varieties sowed in spring in different developmental stages were observed. Jointing and flowering stages were the critical periods for regulation of endogenous hormones. Path analysis and multiple stepwise regression analysis indicated that partial correlation coefficients of endogenous hormones at jointing stage (GA and ABA) and flowering stage (ZR and GA) had obviously positive effect on grain weight, and partial correlation coefficients of them with yield were 0.88~0.91, and 0.995~0.997, respectively. GA contents were more correlated with the production. The difference in endogenous hormones of cultivars was greater than that of sowing dates. GA contents of Yangmai 13 was more stable,and ABA contents was obviously lower than others. The ratios of GA to ABA、IAA to ABA、ZR to ABA、and (GA+ IAA+ ZR) to ABA in Yangmai 13 were higher than those in Yumai 10. The above mentioned results suggested that Yangmai 13 had stronger ability to regulate endogenous hormone contents for adapting different environments under winter wheat varieties sowed in spring. Grain yield, spike number and grain number per spike of Yangmai 13 were significantly higher than those of Yumai 10 and Ning 2038, and yield of Yangmai 13 in early sowing treatments were obviously high. The theoretical reference was provided for the growth and yield formation of winter wheat varieties sowed in spring regulated by the endogenous hormone research.