A recombinant BCG vaccine being transformed with an expression vector that has a polynucleotide encoding a foreign antigenic protein, wherein the polynucleotide is a modified one in which the third position of each codon is substituted with G or C without a change of an amino acid. This recombinant BCG vaccine has an excellent expression rate of antigenic protein and, as a result, capable of inducing a sufficient immune response against target infectious disease, cancer, or the like at the same dose as that of the typical BCG vaccine.