Abstract: A method of haematoxylin staining used for revealing the heterochromatic zone of chromosomes in Vicia faba was reported. It was compared with the method of Feulgen reaction after low temperature treatment, and differenc and resemblance between them were analysed. Based upon the experimental results of this report and the data from of others authors work, the authors suggest that certain transitional degrees between the typical heterochromatic and euchromatic zones should be present. The heterochromatic zone of M-chromosome in Vicia faba was then divided primarily into 5 degrees and the nature of them was discussed.