Abstract: Petiole of 12 Machilus plants was taken as the research object. The anatomical characteristics of transverse section of the central part of petiole were observed under light microscope with paraffin section method.The results showed that the central shape of petiole of 12 Machilus can be divided into Ω shape and horseshoe shape. The types of the upper petioles shape could be fell into two broad headings, concave and convex. The shape in epidermis cells of petiole were rectangle or nearly circular, vascular bundle length-width ratio, petioles length-width ratio and lower epidermis to the vascular bundle relative distance ratio were also different, which those differences micromorphological characters could serve as one of the criteria to identify species of taxonomic Machilus. In addition, the number and distribution of oil and mucilage cells also had a certain reference role in plant classification of Machilus.