Abstract: The paraffin cut method was used to observe the flower bud differentiation of Tilia miqueliana. The results showed that Tilia miqueliana hiemal bud belonged to mixed bud. After the sprout of mixed bud, flower bud was formed in leaf axil. Flower bud was differentiated in the same year from the end of March to the early May, i. e., it took about 35 to 40 days totally. The flower bud differentiation was that of short duration and fast development. The differentiation included two processes with inflorescence differentiation and floret differentiation. All flower bud differentiation was divided into seven developmental stages, i. e., initial differentiation phase, inflorescence primordium differentiation phase, floret primordium differentiation phase, sepal primordium differentiation phase, petal primordium differentiation phase, stamen primordimn differentiation phase and pistil primordum differentiation phase.