The Results of colchicine and pretreatment time have shown that the cells of Coho Salmon(Oncorhynchus Kisutch) were effectively injected 6 hours prior to the harvest at a final concentration of 10$mu extrm{g}$/g body weight. The cell-density from 8,000 cells/㎣ (=8${ imes}$106 ml) was found as ideal. The best effect of hypotonic solution in proportion to the cell is 20 : 1 and 50 minutes. The model number of diploid chromosome in this species was 2n=60. The karyotype analysis proved that the diploid complement consisted of 19 pairs of metacentric-, 4 pairs of submetacentric- and 7 paris of acrocentric-chromosomes. The diagrammatic representation proved that the diploid complement consisted of 7 pairs of metacentric-, 2 pairs of submetacentric- and 1 pair of acrocentric-chromosomes.