AIM: To clone and construct an eukaryotic expression plasmid containing β5 subunit gene, in order to study the mechanism of age-related cataract formation and the prevention measure. ·METHODS: Total RNA was extracted from human lens epithelium strain SRA01/04. β5 subunit cDNA was ampli-fied by RT-PCR, ligated into the eukaryotic expression vector pcDNA3.1(+).·RESULTS: RT-PCR product is about 792bp specific segement. Analysis by estricting enzyme EcoRⅠand HindⅢ and DNA sequence showed the inserted β5 subunit gene was correct.·CONCLUSION: Eukaryotic expression plasimd pcDNA 3.1-β5 is successfully constructed in order to make a basis for the further reseach.