Abstract: Variation degree,correlation coefficient and principal component of 9 traits of Kosteletzkya virginica were analyzed,which involved seed yield,plant height,collar diameter,the number of branches,hundredseed weight,the number of seeds,germination capacity,protein content and crude fat content,respectively.The results showed that it was necessary to improve natural population of Kosteletzkya virginica for the high seed yield and good quality.Both collar diameter and the number of branches were significantly positively correlated with seed yield(r=0.788 and 0.709,respectively).Crude fat content and plant height were correlated with seed yield(r=0.380 and 0.279).Both protein content and crude fat content were correlated with collar diameter(r=0.308 and 0.342).Nine quantitative traits of Kosteletzkya virginica could be divided into 4 principal components by principal component analysis,that is the yield factor,plant height factor,hundredseed weight factor and quality factor,these additive contribute proportions were 77.176%.For the breeding of a new line or variety with high yield and good quality,the principles are to be followed in the terms of the contribution of the principal component: firstly,select the line or variety with big collar diameter and more branch,then combine more the number of seeds with high yield,finally select a fine line or variety with high quality.