Abstract: Using the method of principal component analysis, starting from the sample correlation matrix, analysis was made of 8 main characters (by three-diameter average size, shell thickness, nut weight, kernel weight,kernel rate,crude fat,protein,per unit area yield of walnut kernel weight crown projection) of fine individuals of 9 walnut varieties. Taking the cumulative variance contribution rate of the characters reaching 82.751% as the standard,the main composition and function of two main economic traits were determined,able to display the main characters of walnuts in Panzhihua city. By the nut character comparison of samples,the excellent samples with comprehensive economic characters were finally selected.