Seven macaque species, known as the Sulawesi macaques, rapidly diverged from the common ancestor in Sulawesi island within 0.35 million years. Distinguishing from the other macaques, Sulawesi macaques commonly have dark coat color, with color brightness and color pattern diversified within the seven species. MC1R plays a key role in regulating synthesis of the dark eumelanin and the red/yellow pheomelanin in mammals. We investigated nucleotide sequences of MC1R gene from 11 individuals each for five species, M. nigra, M. nigrescens, M. hecki, M. tonkeana and M. maura, 3 individuals for M. ocheata and 2 individuals for M. brunescens. We identified 27 single-nucleotide polymorphisms (SNPs), of which 10 SNPs resulted in species-specific nonsynonymous variants. All the 10 nonsynonymous substitutions responsible for six species-specific haplotypes, while M. ocheata and M. brunescens shared the amino acid haplotype. We predicted that 5 amino acid substitutions do affect MC1R function. We tested the functional property of agonist α-MSH binding activity of fixed variants. We found that the MC1R variants exhibited variation in agonist binding ability and basal activity by using cAMP assay. Our results so far suggested that fixation of MC1R occurred among Sulawesi macaques, and MC1R variants evolved into different functional characteristic among species.