This paper communicates our hew findings on a mutant of Monascus mold which is capable of producing a high concentration of yellow pigments (lambda(max) 370 nm) instead of red pigments (lambda(max) 420 and 500 nm) produced by its parent strains. Various factors affecting yellow pigment production have been examined. It was found that the mutant produced the maximal amount of pigment under the optimal conditions for pigment production of its parent strains. The mutation allowed a 10-fold increase in both yellow pigment production and amylolytic enzyme activity over those from a yellow pigment producer isolated previously by us.