104 Lactic acid bacteria （LAB）， with different colony morphology， were selected from traditional fermented food produced in different regions. Through the hydrogen peroxide resistance tests， 20 LAB with antioxidant capacity were screened and the ability to produce superoxide dismutase （SOD） were determined. The results indicated that C8 showed the highest SOD activity among 20 LAB， reaching 349.62 U/mg. Then gram staining， catalase experiments， and 16S rRNA gene sequence analysis were conducted to the identification of C8. Phylogenetic trees were constructed and C8 was determined as Lactococcus lactic according to the homology analysis. In order to improve the ability of Lactococcus lactic to produce SOD， the effects of fermentation temperature， initial inoculation amount， initial pH value and liquid volume on the activity of SOD were explored through single factor experiments， and the fermentation conditions were further optimized through orthogonal experiments. Finally， the optimal fermentation conditions were determined： fermentation temperature 37 ℃， initial inoculation volume 3%， initial pH 7.5， liquid volume 75 mL. The activity of SOD reached to 93.95 U/mL under the optimized fermentation conditions， which was 2.2 times than before， providing a foundation for the application of Lactococcus lactis in fermentation industry.