The feature of a new type of ventilatory structure in vascular plant named as the “raised pore” in Christensenia assamicas leaves were observed by using paraffin section and SEM for the first time. The results showed that: (1) the raised pore was comprised of around 20 strip cells, like a raised upsidedown bowl on the outer epidermis under leaves, massive microvilli are distributed on the intine of the raised part, and there is a round hole on the top that cannot be opened or closed which diameter is about 240 μm; (2) The photosynthetic cells liked tubular branches are contained in the air chamber under the raised pore and massive microvilli are distributed on them; (3) With the transition from the air chamber to the leaf vein, microvilli gradually changed into microfibrils and striplike plaques; (4) The appearance of the raised pore is similar with hepaticas single stomata of bryophytes, but cell differentiation is more complicated than the latter. It is considered that the raised pore is a kind of ventilatory structure in vascular plant with the largest diameter found so far, can neither be opened nor closed, and has high efficiency in terms of gas metabolism and special defense function. It may be related to the morphological evolution of hepaticas single stomata of bryophytes.