An attempt was made in the present study to express mouse tyrosinase cDNAs fused with the authentic genomic 5' non-coding flanking sequence in cultured albino melanocytes. One of the cDNA sequences, which expressed successfully and produced melanin pigments, was analyzed with respect to deduced amino acid sequence. Sequencing of the tyrosinase genomic gene revealed the existence of several sets of a characteristic structure which consists of a chain of two successive stem structures, CCAAT-homology and TATA box at its 5' non-coding region. It seems possible that this region represents the regulatory element of the tyrosinase gene. Unusually long GA cluster at 5' upstream region was also found.