Abstract: In the genus Cedrus Trew there are currently 4 species- C. deodara, C. atlantica, C. libani and C. brevifolia,, which disjunctly distribute in the north-western Himalayas (India and eastern Afghanistan), in the north-western Africa (eastern Morocco to Algeria) and in the western Asia (Lebanon, Syria, southern Turkey, the Island of Cyprus). The present paper deals with the karyotype analysis of Cedrus deodara. The karyotype formula of the species is K(2n)=24= 18m+6sm, which is the same as that of Hizume's (1988) and different from that of Mehra & Khoshoo's (1965). The karyotypes of three represent species of Cedrus are compared and there may be a trend from primitive to advanced as C. deodara -^ C. atlantica -* C. libani. Accord-ing to the comparison among the karyotypes of pinaceous genera, the author considers that it is desirable to separate Cedrus from Laricoideae and put it into Abietoideae. Based on the data of cytology, fossil, geographical distribution, palaeogeography and palaeoclimate, etc., the present paper discussed the origin, the migration and the evolution of Cedrus.

Key words: Cedrus