Phenotypic diversity of walnut germplasm resources were investigated from main characters through variation analysis, clustering analysis and principal component analysis based on 411 superior trees from 15 cities/counties in Sichuan. The results were gotten as follows: ① variation coefficients of many economic indicators, such as fruit branches percentage, nut appearance, suture line, difficulty of taking kernel out and shell thickness were in a relative high level, they were 53.2%, 34.4%, 37.4%, 25.7% and 23.4% respectively. Consequently, the four indicators could be considered as reference guides in walnut variety breeding. ② the variation extent of all walnut characters was the greatest in Shimian area among all 15 walnut growing areas, where the genetic diversity showed great abundance. In general, the walnut from Batang area was ranked first in the 15 walnut areas; ③ the result from cluster analysis showed that the 15 walnut areas could be clustered into 2 classes when the distance was 25, i.e., the first class was distributed in Maoxian, Batang, Xiangcheng, Deronga, Jiuzhaigou, Wenchuan, Xiaojin, Songpan, Jiulong and Maerkang, and the second class was distributed in Meigu, Muli, Dechang, Mianzhu and Shimian. The result showed that the phenotypic characteristics of nuts had close relation with climatic condition, and fruit branches percentage could be taken as an important indicator for walnut zoning.