The word karyotype was first put forward by Soviet scholars T.A. Levitchi and Jidelonge in the 1920s. 1952, Tao Chiuh Hsu, an American cytologist, first used hypotonic treatment technology to disperse chromosomes in cells for easy observation. Later, the application of colchicine stopped the proliferating cells at metaphase, so it was easy to obtain a large number of metaphase phases for observation. The discovery that phytohemagglutinin (PHA) stimulates white blood cell division makes it possible to observe animal and human chromosomes through blood culture. With the improvement of various culture, production and dyeing techniques, karyotype research has entered a new stage of vigorous development. 1956 Swedish cytogenetics Jia Zhuang Youxing and others reported that the number of human chromosomes is 46, not 48 as previously thought. After 1959, more and more chromosomal abnormalities were found in humans. 1960 At the international academic conference held in Denver, USA in April, the terms, symbols and methods of grouping and naming human chromosomes were uniformly stipulated. The Standing Committee of Human Chromosome Nomenclature, which was produced by the Fifth International Conference on Human Genetics, held a special meeting in 1977 to revise it. After the meeting, the International Nomenclature System of Human Cytogenetics (ISCN) (1978) was published. 198 1 year, the Committee published the International System of High Resolution Zonal Naming in Human Cytogenetics. Based on the naming rules of metaphase chromosomes formulated by 1977, the naming rules and pattern diagrams of high resolution metaphase chromosomes were put forward. These regulations are widely adopted by scholars all over the world.