Abstract: To select high yield cultivars of Brassica napus L.well suited to climatic conditions in mountainous dry land from Northwest China,twenty varieties with potential yield were compared in the field.The relationship between yield and main plant characters as well as three yield components were analyzed using grey correlation method.The grey correlation degree of plant characters with yield in the order of maximum to minimum was length of main inflorescence>number of second branches>stem diameter>length of pod>plant weight>number of first branches.The grey correlation degree of yield components with yield itself in the order of maximum to minimum was pod number per plant>seed number per pod>thousand-grain weight.The yield in cultivars Mianyou11,Sanfeng19,h056,h067 and Sanfeng16 was 121.8%,85.7%,83.6%,78.4% and 68.9% greater respectively than that of check cultivar Qingza 3.