To explore the internal relationship between embryo morphology, physiological and biochemical changes and dormancy release of Sinopodophyllum hexandrum seeds in the process of low temperature stratification, we relieved seed dormancy by low temperature stratification treatment in this study. The changes of embryo morphology, embryo rate, germination, content of nutrients (starch, soluble protein,soluble sugar), levels of endogenous hormones［gibberellin (GA), indoleacetic acid (IAA), abscisic acid (ABA)］ and activities of key ratelimiting enzymes in respiratory pathway ［pyruvate kinase (PK), succinate dehydrogenase (SDH) and 6phosphateglucose dehydrogenase (G6PDH)］ were measured at different stratification time points. The results showed that: (1) the seed embryo of S. hexandrum was torpedo or cotyledon embryo, the germination rate of seeds increased significantly at the late stage of stratification (60-75 days) (P < 0.05). (2) During stratification, pyruvate kinase (PK) activity and succinate dehydrogenase (SDH) activity decreased significantly(P＜0.05), while soluble protein content and indoleacetic acid (IAA) content increased significantly (P＜0.05), and the ratio of germination promoters and inhibitors (GA/ABA, IAA/ABA, GA+IAA/ABA) also increased. (3) Seed embryo rate was negatively correlated with soluble sugar content, and seed germination rate was positively correlated with soluble protein content. It was found that there was no morphological dormancy in S. hexandrum seeds, the decomposition and transformation of nutrients in seeds provided energy for various metabolic activities in the process of seed dormancy release, and starch was probably the most important energy supplying substance in this process, and the activation of pentose phosphate pathway (PPP), the increase of the proportion of germination promoters and inhibitors (GA/ABA, IAA/ABA, GA+IAA/ABA) and the significant increase of IAA content were the key to dormancy release.