【Objective】The changes in endogenous hormone content were studied during flower bud differentiation in three grape varieties in order to study the physiological mechanism of bud differentiation and growth. 【Method】During the flower bud differentiation stage in three grapes varieties （Kyoho， Victoria and Cabernet Sauvignon）， contents of four endogenous hormones， viz.， IAA， GA3， ZRs and ABA were measured using enzyme linked immunosorbent assay （ELISA） kit. 【Result】During flower bud differentiation stage， IAA content in three grape varieties decreased initially， but later increased slightly. GA3 content in three grapes varieties gradually dropped and plunged to very low level finally. ZRs content in three grapes varieties reduced at beginning， but increased greatly with time. ABA content in Victoria and Cabernet Sauvignon showed gradual decreasing trend at first， however that in Kyoho increased initially before fell sharply afterwards. ABA content in three grape varieties maintained at a stable level during later stage. 【Conclusion】It is concluded that flower bud differentiation in three grape varieties needs higher concentration of ZRs， while low and very low concentration of GA3 and IAA， respectively.