Abstract: 【Objective】 This paper is to probe the relationship and genetic diversity of the winter wheat varieties that selected from liberation to now in Shandong Province. 【Method】 The coefficient parentage is used to analyze the 2145 combinations of 66 winter wheat varieties in nine varieties exchanging. 【Result】 It showed that the relationship exists among 67.44% combinations, the range of COP value of all varieties is 0.00-0.8203 with the average value 0.06249, 21.53% of pedigrees Relationship Coefficients (RC) are higher than the average. The RC of varieties of every year became bigger along with the time, fell in the 90's, and then increased again. The varieties RCs in each year were bigger than that between years, less that that between early and present varieties, while became larger between medium-term and latter varieties. The variety genetic contributions of the same age decreases with the time. The result of clustering analysis on varieties COP values on the basis of the WAP method showed that 63 varieties can be united into 6 big clusters based on different years, and the left three varieties, Xuzhou438, Qida195, Yannong 78 were made into a cluster at the value of 0. The RCs of the 17 varieties which have been extended many area for a long time in Shandong Province were little, with bigger genetic difference, and all those varieties were selected from overseas parents' combinations. The breeding genetic resources of Shandong Province can be traced back to four big core parents system of Biyu, Villa Glori (Zhongnong 28), Luofulin and Youzi wheat on the ground of pedigree analysis. 【Conclusion】 The genetic differences and diversity between varieties were little by little after 1950's.

Key words: winter wheat, relation coefficient, genetic diversity, pedigree