Six different polyploid loaches (DD×PP-0,3n=74; DD×DD0,3n=75; DD×TT-0,4n=100; TT×PP-0,5n=124; TT×DD-0,5n=125 and TT×TT-0,6n=150. Female in the former) were induced using large scale loach (Paramisgurnus dabryanus,PP),diploid (DD),and tetraploid (TT) dojo loach (Misgurnus anguillicaudatus) by cold shock. The cold shock was maintained for 30-35 min using 23 ℃ icewater from 5 min after fertilization. The ploidy of induced progenies at different development stages were measured by flow cytometry. The results showed that the ratios of induced triploid progenies were 87.50% of DD×PP-0,53.85% of DD×DD-0,90.91% of DD×TT-0,84.96% of TT×PP-0,76.92% of TT×DD-0,and 12.5% of TT×TT-0 at 1 month of age. The ratios of induced polyploidy progenies were 91.43% (DD×PP-0,3n=74),60% (DD×DD-0,3n=75),85.19% (DD×TT-0,4n=100),83.33% (TT×PP-0,5n=124),87.50% (TT×DD-0,5n=125) and 6.06% (TT×TT-0,6n=150) at 12 months of age,respectively. The ploidy composition of each group at 12 months was similar to that at 1 month of age. The ratio of induced polyploid progenies decreased with increasing ploidy levels. Growth performance of each group was measured and analyzed by statistical analysis. Little difference was observed at early development stage,while significant difference was observed at 12 months of age. The progenies of TT×PP-0 had the highest total length and body weight value at 12 months of age. Furthermore,the fertilization cytology observation confirmed that the second polar body was retained in fertilized ovum by cold shock to produce triploidtype progenies.