In order to dissect the relationship between hypocotyl length，root length at seedling stage and main agronomic traits and quality traits at maturity stage of Brassica napus,125 varieties (lines) of B.na pus were planted indoors and in field for investigating their agricultural traits and quality traits.Correlation and gray relational grade analyses were conducted among various traits.Results showed that the variation coefficients of erucic acid content and glucosinolate content were larger,susceptible to environmental im pact,while the variation coefficients of oil content,plant height were smaller and heritability was higher.The hypocotyl length and the root length at seedling stage was positively correlated with each other. The root length at seedling stage was significantly negative correlated with lodging grade.The length of hypo cotyl and root at seedling stage showed positive correlation with main quality traits and hypocotyl length was positivly correlated with erucic acid content(P＜0.05) .All the results indicated that when the roots of the seedlings were more developed，the lodging resistance and quality traits were better at maturity,and the hypocotyl length and root length at seedling stage could be used as important reference indexes for breeding B.napus with lodging resistance and high quality．