During the sprouting stage in ratoon crop of sugarcane,with the methods of ELISA and bottom part sampling,we studied the relationship of changes in endogenous hormone between good (‘CYZ06-407’ and ‘CYZ06-415’) and poor (‘CYZ06-408’ and ‘CYZ06-416’) ratoonability sugarcane lines generated from one family ‘CYT97-20’×ROC25,where,good ratooning sugarcane cultivar ROC22 was used as control.The result indicated that:(1)The changes in content of IAA,content of ZR and the ratio of ZR/IAA in bottom part of stalk for good/poor ratooning lines were strong during sprouting stage.No significant difference were found between good and poor ratooning lines.(2)At bottom parts of cane stalk,the changes in content of GA₃,content of ABA,ratios of IAA/ABA and ratios of GA₃/ABA between good and poor ratooning lines differed significantly.The most significant difference were found in content of ABA,ratios of IAA/ABA and ratios of GA₃/ABA,which were important parameters;(3)Higher content of ABA in good ratooning lines than that in poor ones,lower ratios of IAA/ABA and ratio of GA₃/ABA than that in poor ones,with the declines in ratoonability,the ratios of IAA/ABA and GA₃/ABA increased.The result suggested good ratoonability was characterized high content of ABA and low ratios of IAA/ABA and GA₃/ABA,among which,content of ABA is the most important parameter for evaluating ratoonability.Meanwhile,other two important parameters IAA/ABA and GA₃/ABA ratios were recommended as well.