Abstract:Bud primordia of Tussilago farfara L. inflorescence at various growth stages were used as experiment materials in this study. By means of paraffin sections, the morphological process of bud differentiation was observed by optical microscope. The results showed that inflorescence differentiation started in the early July and completed in the early October. The whole differentiation process could be divided into ten stages (phases): pre-differentiation, disc formation, inflorescence primordium differentiation, petal primordium differentiation of central flowers (tubiform florets), stamen primordium differentiation of central flowers, pistil primordium differentiation of central flowers, petal primordium differentiation of marginal flowers (ligulate flowers), pistil primordium differentiation of marginal flowers, pollen differentiation of central flowers, ovary and ovule differentiation. The relationship between bud differentiation and the growth period of T.farfara L. was also discussed.