The effect of cattle breed on stearoyl-CoA desaturase (SCD) gene expression was investigated in this study. Detailed comparisons of SCD mRNA level were made among three steers each of Japanese Black, Holstein and their crossbreed which were age-matched had been fed the same diet and were sampled by biopsy of the longissimus dorsi (LD) muscle and subcutaneous fat. The levels of SCD mRNA were measured in samples of muscle and subcutaneous fat. The levels of SCD mRNA demonstrated a breed effect in each tissue, though the relative expression was higher ( P<0.05) in subcutaneous fat. The ratio of SCD mRNA to glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA for Japanese Black, crossbreed and Holstein were 132.1±34.1, 73.5±22.7 and 39.5±12.9, respectively, and significant ( P<0.05) differences existed between Japanese Black and Holstein cattle. Japanese Black subcutaneous fat had consistently higher ( P<0.05) monounsaturated fatty acids (MUFA) percentage than Holstein subcutaneous fat. These results suggest that differences in SCD gene expression may contribute to the fatty acid compositional differences seen between subcutaneous adipose tissue of Japanese Black cattle and Holstein.