Abstract: In this paper reports that the so-called "Mohe Korean pine", found in Daxinganling in the late fifties of this century was proved to be of Pinus sibirica (Loud.) Mayr but not of P. koraiensis Sieb. et Zucc. by a series of research and investigation. On the contrary, the P. koraiensis has not distributed in Daxinganling.The main natural area of the P. sibirica is western and central Sibiria. In Daxing anling it only occurs in the northwestern border. That is a first discovery.In identification, the openings of the sunken stomata on the needles epidermis and their prints on the cuticle, in addition to general morphological characteristics, were also studied camparatively by combination means of dissecting, optical and scanning electron microscope. In this research discovered that the opennings of the sunken stomata, even in the epidermal cells, of the P. sibirica apparently differs from that of the P. koraiensis. That could be considred as a reliable diagnostic characteristics.

Key words: Pinus sibirica, Pinus koraiensis, Daxinganling, Opening of sunken stomata