Antimicrobial activity of Caesalpina sappan L. extract (CS extract) against 6 kinds of food spoilage and pathogenic organisms was studied. The growth of Listeria monocytogenes Brie 1, Escherichis coli ATCC 11775, Staphylococcus aureus ATCC 11775, and Pseudomonas fluorescens ATCC 11775 was inhibited about 4 to 5 $log_{10}$ cycle in Tryptic soy Broth(TSB) containing 1% CS extract. Bacillus subtilis KCTC 102 and Vibrio parahaemolyticus ACTT 17802 did not show apparent growth in the same medium. Effect of CS extract on preservation of ground meat was also investigated. The range of pH change was 5.0~5.2 in CS extract added ground meat, 5.2~6.0 in CS extract not added ground meat (control) during storage at 4$^{circ}C$ for 30 days. Number of total bacteria after 15 days storage was $10^{6}$/g in CS extract added ground meat, 10$^3$/g in control. Redness of ground meats was improved significantly by addition of 1% CS extract during storage at 4$^{circ}C$ for 30 days. The sensory quality of 1% CS extract added hamburger patty was similar to that of the control in taste, flavor, and overall acceptability.