Antimicrobial activity of yellow pigment produced by Monascus anka Y7 (Y7) was studied. The crude yellow pigment of Y7 showed antimicrobial activity against some bacteria and yeasts. The diameter of inhibition zone against gram-positive bacteria was a little smaller t]fan that of gram-negative bacteria to the crude yellow pigment. Especially, E2 fraction obtained from the crude yellow pigment by TLC method showed high anti-microbial activity against E. coli.. The fraction had bright yellow pigment, showing fluorescent light and having the maximum absorption at 373 nm. Citrinin, a mycotoxin which had been characterized as an antimicrobial substance from a Monascus strain, was not detected in the E2 fraction and in the crude yellow pigment by the results of TLC and HPLC. This indicates that the antimicrobial activity of Y7 pigments did not any relationship with citrinin. Yellow degree (b/a of Hunters color value) of Y7 pigment was much higher than that of other natural colorants such as annatto, gardenia yellow and carthamus yellow. But the colors of all of the yellow pigments were similar by panels. Thus, the yellow pigment of Y7 could be used as a useful alternative colorant for food industry, having the advantage of antimicrobial activity.