The green preiods of about 19 varieties of the common cool-zone turfgrasses which were from seven different regions, were studied on the basis of turfgrass introduction and cultural experiment in Lanzhou area.The results were; 1) the green periods of all the varieties studied were longer than those of the warm-zone Chinese lawngrass and buffalograss, of which, the wabash of Kentucky bluegrass was the longest,about 289 days, and the common bentgrass was the shortest, only 218 days; 2) The differences of the ...