The invention relates to a method for constructing an air bladder cell system of blotchy rockcod, which comprises: taking an air bladder tissue of the blotchy rockcod as a material to start primary culture, and culturing the air bladder tissue in a DMEM / F12 liquid medium which contains fetal calf serum, carboxymethyl chito-oligosaccharide, basic fibroblast growth factors, I-type insulin-like growth factors, N-acetyl glucose hydrochloride and culture supernatant of heart cells of the blotchy rockcod in the log phase and has a pH value of between 7.0 and 7.4; and adopting a trypsin digestion method for subculturing. The air bladder cell system of the blotchy rockcod constructed by the method is subcultured for 62 generations currently. The technology is scientific and reasonable, is hopefulto be applied to ecotoxicological research, performs pollution monitoring and safety evaluation on various environmental pollutants in the sea, and can also be applied to separation, identification and in vitro breeding of fish viroids, and research in the aspects of interaction of viruses and host cells, and so on.