In this study, Luculia gratissima ‘Xiangfei’ cuttings were selected as material. The floral reaction was explored by different photoperiod treatments and transferring plants between short day and long day conditions. Meanwhile, the process of flowerbud differentiation under different photoperiods was observed by paraffin section. This study attempted to provide a theoretical basis for flowering control and cultivation of potted plants in L. gratissima ‘Xiangfei’. The results indicated that: (1) L. gratissima ‘Xiangfei’ is a qualitative or obligatory shortday plant, the critical daylength is about 14 h, the suitable daylength for flowering is 10-12 h, and the limited inductive photoperiod is 30 shortday. (2) Under the inductive photoperiod, the period of flower bud differentiation included undifferentiation phase, bract primordium differentiation phase, inflorescence or small flower primordium differentiation phase, perianth primordium differentiation phase, stamen primordium differentiation phase, and pistil primordium differentiation phase. After induced photoperiod treatment for 16 d, all plants completely achieved the transition to flowering. After treatment for 30 days, the flower bud differentiation of all plants was at the stage of perianth primordium formation, the floral determination reached a stable maintenance state and the floral reversion would not occur when transferred to the noninductive photoperiod. (3) Under the uninduced photoperiod of 4 h dark interruption, buds of plants were always in undifferentiation phase of vegetative growth.