Abstract:Amino acid analysis was employed in the study of protein in the stigma and pollen of self-incompatible and self-compatible lines of cabbage ( Brassica oleracea L. var. capitata ); from which distinct differences in the contents of amino acids were found between the two lines. The analysis of variance indicated that the contents of 9 kinds of amino acids in the stigma and 6 kinds in the pollen were comparatively much higher in the self-incompatible ones. Cluster analysis was per-formed in order to delete the factors related to the gene type variance. Unassured variances were abandoned by accurate examination. The threonine and tyrosine contents in the stigma and the glycine and alanine content in the pollen were considered as standards to identify self-incompatibility. In the self-incompatible lines, the above-mentioned amino acid contents were higher than 0.223%, 0.358%, 1.593% and 1.464%, respectively; whereas in the self-compatible lines, they were less than 0.185% ,0.164%, 1.470% and 1.006% correspondingly.