Cold atmospheric plasma (CAP) is a promising non-thermal technology that offers the capability of enzyme denaturation without the destruction of important components. The effect of CAP generated by dielectric barrier discharge (DBD) on endogenous enzyme activity and quality parameters of Hairtail (Trichiurus japonicus) was investigated. DBD voltage (30 kV, 40 kV, and 50 kV) and treatment time (2.5, 5.0, 7.5, 10, and 15 minutes) were employed. In all cases, a significant reduction in endogenous enzyme activity of Hairtail (p<0.05) was observed. Our results showed that the treatment time and voltage, significantly affected endogenous enzyme activity and carbonyl content. Nevertheless, the initial temperature and pH did not show significant changes after plasma treatments. From these results, we conclude that cold atmospheric plasma could be utilized as a good technology to maintain product quality and prolong the shelf life.