This paper deals with the establiahment of a heteroploid cell line. designatedCAB--80, which originally comes from the culture of blastulae embryonic cells ofcrucian carp (Carassius auratus L.). Some biological characteristics of this cell lineare described briefly. The conditions used in primary cell culture and subculture areTC--199 medium containing a moderate amount of antibiotics and 20% calf serum andincubated at temperature 27--28℃,pH 7.2. A heteroploid cell line has ban established through 100 subculture passage over a period of 24 months.The cell line consists of epithelial like cells in a great measure and a few fibroblastlike cells.The optimum growth conditions of CAB--80 is at temperature 22--28℃ and pHvalue range at 7.2--8.2. The time for doubling CAB--80 cell population requires 21-45 hours. After incubation for 24 hours, the mitotic index of CAB--80 is 29.5‰. Thedistribution of chromosome numbers of 60th passage cells are ranged from 68 to 178,so it is heterploid cell line. The experiment shows that the CAB-80 cells have somewhat cytopathogenic effectto reovirus infection. It may be used as a bioassay indicator for fish virus.