Taking leaves and flower buds of Juglans sigillata as materials, we observed female bud physiological differentiation stage by paraffin method and determined the contents of chlorophyll and essential minerals nutritions in leaves by method of spectrophotometry, kjeldahl, molybdenum antimony colorimetric and ASS. We also analyzed hormones content in leaves, female bud and male bud by HPLCMS to research the relationship between chlorophyll, mineral nutritions and hormone contents and flower bud differentiation of J. sigillata. The results showed that: (1) The contents of chlorophyll a and chlorophyll b increased before female flower bud physiological differentiation, and present peak at morphological differentiation stage. (2) From physiological differentiation to the morphological differentiation, Ca and Mg contents reduced, K content increased. In the process of flower bud differentiation, P content showed a trend of declining, Fe content increased then fell, Zn content showed ‘M’ type. (3) GA₄ content in leaves and female flower buds fell sharply at physiological differentiation stage and present peak at morphological differentiation stage. ABA and ZR contents showed bimodal curve ‘M’ type in the process of flower bud differentiation. ZR content in the leaves showed a trend of low content continuously, and has a peak at physiological differentiation stage of female flower bud. The content of IAA was low during early morphological differentiation of flower buds. So, it is the critical period of female flower bud that transformed from physiological differentiation to morphological differentiation between the end of April and the middle of May. High content of chlorophyll in leaves and low contents of IAA, GA₄ in female flowers bud were beneficial to female buds early develop. A large amount of P was consumed during flower bud differentiation. High content of K is close to the critical period of female flower buds differentiation and Ca, Mg, Zn contents closely associated with female flower buds morphological differentiation. At the same time, the high contents of ABA, ZR in female flower buds have significant effect to both physiological and morphological differentiation, and high content of GA₄ involved in formation of flower primordium.