The TsR and n561A are strains established in recent years. TsR strains were screened from F2 segregation populations collected what you want the extremely specific phenotype. The n561A was labeled by RFID:145246561A, which selected performance according to the shape of body and sex ratio of family, cross another male from the same family establish F1 , then continuously back crossBC1F1, BC2F1 to establish. Cold resistant traits TsR strain as a contributor cross with n561A, improved n561A strain of cold resistant traits. The n561A was growing up fast and large body shape, which can do recipients of cold resistant traits. The descendants selected a group of individuals who could stay at 8.5 °C for 1 hour, and established a group of recombinant inbred F2 593 and backcross line BC1F1 660. In the F2 cold resistant test, the ability to cold resistant was significantly higher than that of F1 (TsR×n561A) and parentaln 561A (13°C) above 3°C, which is almost equivalent to the parental TsR (8.5°C). It shows that the cold resistance of F2 was better than that of the parental n561A, It is expected that the TsR strain will continue to improve the cold resistant traits of the n561A strain and establish a breeding method for the growth of the tilapia and increase the profits of the aquaculture industry so as to enhance industrial competitiveness.