Connexin 31(Cx31) is one of the human genetic deafness disease genes. To determine the structure and function of Cx31 gene of mouse, the mouse Cx31 gene clone was screened from the genomic library with the probe obtained according to the sequence of the mouse Cx31 gene cDNA. Cx31 gene was mapped to the center of mouse chromosome 4 by fluorescence in situ hybridization. The present study lays a foundation for researches on structure and function of Cx31 gene, as well as establishment of the relative transgenic mice and gene knockout mice.