The invention relates to a gene of high expression lysine, which belongs to the technical field of the biological engineering. The nucleotide sequence of the gene of the high expression lysine is shown as SEQDNO:1, the protein is coded by the gene of the high expression lysine, and the amino acid sequence of the gene of the high expression lysine is shown as SEQIDNO:2. Protein products with high expression lysine content in transgenic mice milk can obviously enhance the content of lysine in the milk. The researches on the lysine transgenic mice can enable people to further understand foreign protein of mammary gland, especially the secretion mechanism of the foreign protein with high lysine content chosen by the research, and establish the foundation for the development of lysine gene milk.