97 walnut germplasm resources from 3 counties of Sichuan province were used as materials, 11 main quantitative characters of walnut were studied to establish the probability grading standards of walnuts and index system on traits evaluation, the results were as follows: The genetic diversity of walnut in Sichuan showed abundance, and the range of variation coefficients of nut characters was from 9.92% to 32.94%. The characters of nut weight, kernel weight, protein content and shell thickness havehigher variation coefficient and could be used as important reference index for walnut breeding; The 11 quantitative characteristics showed a normal distribution with analyzing of K–S and were divided into 5 grades by dividing points of (X–1.281 8S), (X–0.524 6S), (X+0.524 6S) and(X+1.281 8S). Occurrence frequency of 1 to 5 grades was 10%, 20%, 40%, 20% and 10%, respectively.