Abstract:In this paper, the authors make a systematic study on the High-Resolution G-banding technique of plant chromosomes. The improved urea method was successfully used for the first time to introduce G-banding in Triticum boeoticum, Zea mays, Vicia faba, Chlorophytum ce.pense, Lilium davidii, and some other plants. The G-bands which distribute in the entire length of the chromosomes are clear and abundant. They display granular state in the prophase and banded state in the metaphase. The G-bands described above are quite similar to those of mammalian chromosomes. The number of G-bands is dependent on the degree of chromosomal contraction. Another feature observed is that one dark band seen in the metaphase could De distinguished to 2.67 subbands in the late prophase. The band showing effects of the urea method have been compared with those of the trypsin method. The result indicates that the bands shown with these two methods are basically identical. But the effect of urea is much more mitigative than that of trypsin. The band showing time of urea is as long as several minutes. So it is easy to be controled and repeated. Therefore, the urea method has a higher applied value in the study of High-Resolution G-bands of plant chromosomes at present.