Abstract: A diploid fish cell line, named GCCF-2, from grass carp caudalfin was established. The line was cultivated in TC-199 medium with 15% fetal calfserum containing a moderate amount of antibiotics. The morphology of GCCF-2 cellsis a complex of epithelial-like cells, fibroblastic-like cells and the medial type cells.Thecells can increase five times in five days and the highest mitotic index of GCCF-2 is30. 04%in two dayse after plating. An interesting discovery was observed that the cellswhich had been kept in the incubator at 20℃ for two months without any care couldgrow normally after subculture. At the 90th passage, the cells which had a normalnumber of chromosomes of grass carp (2n=48)accounted for 86.7%, so the linewas determined as a diploid fish cell line. So far, the line hes been maintained inproliferating for over 32 months. Using the technique of BrdU-labeling and sisterchromatid differential staining, we estimate the cell cycle time of mitotie division ofGCCF-2 is between 21--33 hours. GCCF-2 was observed to be susceptible infectionwith grass carp reovirus (GCRV).