Bacteriocin J105 is a proteinaceous inhibitory substance produced by Latococcus latis subsp. lactis j105 isolated from Kimchi. Bacteriocin J105 was purified to homogeneity by the pH-dependent adsorption-desorption method and reverse-phase HPLC from the culture broth of Lactococcus lactis subsp. lactis J105. Purification of bacteriocin J105 resulted in a 1.47-fold increase in the specific activity and the recovery was 1.5%. Its molecular mass measured by the electrophoretic pattern in the sodium, dodecyl sulfate polyacrylamide gel was about 3.4 kDa. It was stable at $121^{circ}C$ for 15 min at pH between 2 and 4. However, at pH above 5, bacteriocin was rapidly inactivated. Twenty-one residues from the N-terminal portion of bacteriocin J105 were sequenced using sequence analysis of lantibiotics. Bacteriocin J105 showed significant homology with known nisin A from lactic acid bacteria.