A bacterial strain HJ-14 was isolated as a producer of antioxidants from the coast of Jinhae in Korea. The isolate showed 43.4mol% of G+C content, and contained dihydrogenated ubiquinone with Q8 as a major quinone. Chemotaxonomic analysis as well as phylogenetic analysis, based on the 16S rDNA sequence, identified the isolate as a member of Alteromonas macleodii. For antioxidant production, the optimum medium composition was determined to be 3% dextrin, 0.5% ammonium sulfate, and 2-6% sodium chloride. Optimum culture conditions for production of antioxidant materials with strain HJ-14 were at pH 6.0-8.0 and $25-37^{circ}C$. The chloroform extract of strain HJ-14 broth showed 1.96-17.5-fold higher antioxidant activity than other organic solvents in term of electron donating ability.