Recently, fatty acid composition has been recognized as an important economic trait of Japanese Black cattle. The aim of this study was to seek for candidate genes which might be useful for beef breeding to increase the mono-unsaturated fatty acid (MUFA) level. For this purpose, we compared gene expression profile of Japanese Black cattle which showed high percentage of MUFA in their muscle with that of low MUFA group by microarray. Consequently, these groups showed different expression pattern of genes related to fat synthesis and metabolism, such as SPP1 (secreted phosphoprotein-1), LEP(leptin), MMP14 (matrix metallopeptidase 14), IGF1 (insulin-like growth factor-1), FGF1 (fibroblast growth factor-1) and FGF2. Our result suggested that these genes might be useful for marker-assisted selection for increasing the MUFA level in Japanese Black cattle. Identifying the causative mutations which influence function of the genes will help to develop additional DNA markers for beef breeding.