In order to reveal flower formation mechanism of Cymbidium kanran Makino, we documented the floral ontogeny and development of this endangered orchid species by paraffin section and anatomy, with focus on the primitive and middle develop stages of labellum and gynostemium (before the elongation of the column part). Results show that: the differentiation process of inflorescence is acropetal and follows the sequence: inflorescence primordium differentiation, floral primordium differentiation, perianth differentiation, and gynostemium formation. Differentiation of the labellum follows the sequence: lamella, sidelobes, and purplish red patches on the midlobe and stripes on the sidelobes. Because of the late initiation of the sidelobes and lamella of the labellum, they may not be related to the staminodes. During the formation of gynostemium, anther initiates first, then the median carpel apex and lateral carpel apices emerge, stigmatic channel forms, and finally the rostellum and viscidium differentiate.