Abstract: With studying on the technical parameters of cryo-sectioning in floral organs of four plant species, we established a suitable cryo-sectioning method for floral organs of plants. The procedure consisted of several steps as follows.The materials were taken out and fixed in solution contained cryo-protected reagent (sucrose). The fixed samples were embedded, frozen in liquid nitrogen and cryo-sectioned. Then, the sections were dried, stained or not and photographed. This method was better than single liquid freezing or sucrose-protecting or direct cryo-section. The fine structures of ovaries, anthers and shoot apical buds in four plant species were displayed by the sucrose-protecting and liquid nitrogen frozen cryo-sectioning technique. One important point is that the different concentrations of sucrose were used during fixing because of varied plant tissue structures and osmotic pressure, and the sucrose level suitable for the floral organs of the four species were also investigated.