The content changes of endogenous hormones of northeastern Tibetan plateau endemism species Picea crassifolia during flower bud differentiation were determined and analyzed.The results show that:(1)The changes of endogenous hormones GAs,IAA,ZR and ABA were similar;They all have peaks at the earlier stage of flower bud physiology differentiation and morphology differentiation.The ratios of ZR/GAs,ZR/IAA have peaks during flower bud physiological differentiation,while the ratio of ABA/GAs has an increasing trend.(2)During flower bud physiology differentiation,both the soluble sugar and protein in the terminal bud and lateral bud are all in peak;During the early morphology differentiation,the content of protein in the terminal bud and lateral bud decreased,while the soluble sugar content continue to rise,and in the flower bud differentiation,the content of nucleic acid is in a increasing trend.A high rate of ZR/GAs,ZR/IAA is benefited to the flower bud physiological differentiation of P.crassifolia,but might not be necessary for the flower bud morphology differentiation;While a high rate of ABA/ GAs,ABA/IAA might be indispensable.The accumulation of the structure material and energy,such as soluble sugar,protein and nucleic acid is helpful for the completion of the P.crassifolia flower bud differentiation.