Abstract:The G-banding technique has not yet been broken through in studying plant chromosomes. in this paper, we have described a new banding method in Secale cereale. The rye root tips were treated with actinomycin D (40-100 μg/ml) for two hours and with colchicine (0.01%) for 0.5 hour and then fixed with methanol-acetic acid (3:1). After cell wall degradation by cellulase and pectinase, the chromosome sample were made by a hypotonic and flame-drying method (hypotonic treatment→preparation of cell suspension→dropping suspension on slide flame-drying). Following an air-drying period of about a week, the slides were incubated in trypsin-EDTA solution (0.01–0.05%) at 30℃ for 10–15 sec. and subsequently stained with Giemsa. Lots of deep stained bands along the arms of many prophase and late prophase chromosomes were seen. The position of them was obviously different from that of the C-band and the number of them was approximately in proportion to the longitude of chromosomes. Such bands were not seen in metaphase chromosomes. We thought it preferable to use prophase chromosomes to probe G-banding technique in plant and this paper has proposed a possible way for studying G-banding technique in plant chromosome. We also discuss why metaphase chromosomes of plant do not show G-bands.