Provided is a porcine CD28 receptor molecule, which is: 1) a protein consisting of an amino acid sequence represented by SEQ ID NO:2, or 2) a protein derived from 1) by substitution, deletion or addition of one or several amino acids in the amino acid sequence represented by SEQ ID NO:2 and having equivalent activity with 1). Further provided is a gene for coding the porcine CD28 receptor, the nucleotide sequence of which is shown as SEQ ID NO:1. When the provided co-stimulating receptor CD28 is expressed specifically and highly in a T cell, the activation, proliferation and cell factor secretion activity of the T cell when stimulated by an antigen can be enhanced, thereby enhancing the acquired immune response of a host and enhancing the immune effect of a vaccine.
