Abstract: 【Objective】To explore composition features of Tibetan cultivated barley varieties and to shed light on distribution rules in different regions. 【Method】This research is summarized based on Prof. Ma De-quan’s barley classification system and authors’ on-the-pot investigation. 【Result】There are total of 601 cultivated barley varieties, which includes 13 varieties of two-rowed husky barley, 23 varieties of two-rowed naked ones, 7 of four-rowed naked ones, 57 of six-rowed husked ones and 501 of six-rowed naked ones. They express agronomic traits of both six-rowed and naked barley grain. In areas with closer elevation, the cultivated barley variety distribution exhibits evident difference in different sub-regions and concentrates in southeast, northeast and central sub-region of Tibet but scatters in other areas. With elevation rising gradually, the distribution changes in a particular pattern: barley varieties distribute sparsely in the area lower than 2 500 m, distribute in a concentrated way in the regions of 3 000-4 000 m elevation, distribute gradually less when elevation reaches higher than 4 000 m. The analysis of 9 sub-regions’ cultivated barley variety similarity shows that varieties similarity between Zayu-Motuo sub-region and southeast one is much more different from that of the east-west direction one. 【Conclusion】The cultivated barley varieties composition and geographic distribution rules have proved the line of Boshula Mountains-Nanjiabawa Peak-Puoxiong la-Mala a correct boundary as winter barley and spring-winter barley regions.

Key words: Tibet, Cultivated barley, Variety composition, Geographic distribution