To understand the role of type I collagen in pig health and pork production, we report the complete coding sequences of porcine COL1A1 and COL1A2 cDNAs as a first step toward the functional analysis of these genes. The coding sequences of cDNA showed high similarity with those of other mammals (88.6%-95.0% and 86.8%-93.3%, respectively). The deduced amino acid sequences of the porcine COL1A1 and COL1A2 mature proteins showed 91.3%-97.1% and 89.5%-96.0% identity with one of the other mammalian sequences, respectively. Expression analysis showed that these genes were more highly expressed in connective tissues such as skin and back fat than in other tissues. The expression ratio of these two genes is similar in almost all porcine tissues examined, although the COL1A1 gene in back fat and muscle, and the COL1A2 gene in testis are more highly expressed than the other gene.