The invention provides a method for rapidly preparing 
metaphase chromosomes of marine valuable and rare fishes or shellfishes, and belongs to the technical field of marine organisms. The method comprises the steps that 1, test fishes or shellfishes are temporarily cultured, and glass slides are cleaned; 2, after it is guaranteed that the survival state of the test animals is good, the fishes or shellfishes of which fin rays or grills have wounds are selected to be independently cultured; 3, healing and proliferating tissue at the wounds of the test animals is taken to be subjected to 
chromosome preparation. The method for preparing the 
metaphase chromosomes is simple and rapid and convenient to operate, the vigorous division and proliferation capacity of the healing and proliferating tissue is fully utilized, it is basically guaranteed that the test animals still can be healthy and be survived after 
chromosome preparation, multiple times of preparation can be repeated, the needed test animal can be least to one individual, and the method is suitable for various marine valuable and rare fishes and shellfishes. According to the method, freshness of the experiment samples can be guaranteed, the 
cell activity is good, the defects that most of the valuable and rare fishes or shellfishes are in a mature or aged state, and 
cell division is not vigorous are overcome, the prepared 
metaphase chromosomes are good in morphology and dispersion degree, and therefore observation and counting are convenient.