Abstract: The present paper is the investigation for the chromosome banding technique of trypsin-Giemsa in plants. Vicia faba, Allium cepa and Secale cereale were used. The fixed roots were hydrolysed in 0.1 N HCl or 45% acetic acid and squashed in a drop of 45% acetic acid. Coverslips were removed by the freezing method and the slides dried in the air. The preparations were then immersed in 0.025% solution of trypsin in phosphate-buffered saline (pH 7.2) at 34 ℃ for 10–15 minutes. Staining was performed on 10% Giemsa at pH 7.2. This method has some unique features. It is fast and technically simple and C-banding of good-quality can be consistently demonstrated. In this paper the chromosome banding pattern with trypsin-Giemsa in Vicia faba is analyzed and the mechanism of chromosome banding with trypsin-Giemsa is also discussed.