Abstract: In order to study new non-CO color retention method of tilapia fillets and achieve a safe and effective color retention process, we used color difference value as main evaluation index for the fillets' color. Based on single-factor test of sodium nitrite concentration, sodium bicarbonate concentration and soaking time, we used Box-Behnken center design principle to optimize the response surface test of the assay  scheme. The results show that soaking in a composite solution of sodium nitrite concentration of 0.4 g·L⁻¹ and sodium bicarbonate concentration of 5.0 g·L⁻¹ for 22 min performs well. The redness value (Δa^*) of the red meat was 1.97 with an increase of 17.35%. The overall color of the fillets was improved. A new method of non-CO color retention  technology of tilapia fillets is obtained.