Abstract: Hormone changes in the seeds of Kalopanax septemlobus at different stratification conditions were determined by the means of HPLC and bioassay The results showed that two kinds of inhibitory substances——ABA and coumarin existed in the dry teeds. Gibberellic acid (GA₃), indole-acetic acid (IAA) and zeatin (Z) were detected during stratifacation. Based on the characteristics of the dynamic of hormones in the seeds, the changes of hormones in the after-ripening process could be divided into three phases as phasel, phase 2 and phase 3. Phase 1 is in the characteristics of the reduction of ABA, coumarin and IAA levels. In phase 2, GA₃ and Z incrense rapidly while the regulators levels keep relatively stable in the phase 3. The seed dormancy and dormancy and dormancy breaking may depend on the status of phase 2, It is suggested that the embryo differentiation during morphological ripeniog which complete at warm stratification is correlated to the levels of ABA and coumarin, and regulated by GA₃ and IAA. But the physiological ripening which finished at cool stratification is mainly associated with Z level. The results, indicate that the relative level of the promotors and inhibitors may play more important parts than the absolute level of hormones in the seed dormancy.