The present invention discloses a codon-optimized gene encoding major capsid protein L1 of human papilloma virus, which is capable, after transduced into a yeast cell, of efficiently expressing the major capsid protein L1 of human papilloma virus. The present invention also discloses an immunogenic macromolecule which is essentially produced by expression of said codon-optimized gene encoding the major capsid protein L1 of human papilloma virus in a yeast cell. The present invention further discloses the use of said immunogenic macromolecule and a composition comprising said immunogenic macromolecule.