Abstract: There are 970 species, 329 genera, 65 families of seed plants distributed in this area (34.50'-35.55'N and 100.40'-102.30'E). Its floristic characteristics are as follows:(1)The flora is formed under the influence of alpine-arctic and xeric ecological environment. (2) The north temperate elements are superior than the old world temperate elements and others in numbers. (3) The north temperate elements are superior than the old world temperate elements and others in numbers.

Key words: Flora