Biofertilizers are increasingly available in the market as one of the alternatives to chemical fertilizers. The supply of a high number of viable microorganisms is important for farmers. Lysobacter capsici YS1215 producing chitinases and gelatinases, isolated from soil in Korea, was evaluated for the establishment of an optimal medium condition of its shelf life under an in vitro condition. In this study, the population density of a biofertilizer (L. capsici YS1215) in media containing crab shell and gelatin powder (M1, M2, M3 and M4) was observed to be higher than that of populations grown in TSB (Tryptic soy broth) media (M5, M6 and M7) during experimental period. In addition, the population density at 11 months was over 106 CFU mL-1 in M1, M3 and M4, but under 106 CFU mL-1 in M2, M5, M6 and M7. The best optimal medium for the shelf life was M1 (2.6 × 106 CFU mL-1) containing both chitinous and gelatinous materials at 11 months. Therefore, this study provided results of the appropriate medium composition for the enhancement of the shelf life of L. capsici YS1215.