Gene encoding β-glucosidase was amplified through PCR by using the genome DNA extracted from L .delbrueckii subsp. delbrueckii as a template. The gene encoding β-glucosidase was inserted into a prokaryotic expression vector pET-28a(+) and expressed in E.coli strain BL21(DE3). The gene encoding β-glucosidase was of 1380bp. The nucleotide sequence of the gene encoding β-glucosidase from L. delbrueckii subsp. delbrueckii showed as high as 97.9% homology comparing with that from L. delbrueckii subsp. bulgaricus indicating that the gene encoding β-glucosidase is highly conservative. The enzyme activity was about 34U/mg and the molecular weight of β-glucosidase is about 51 kDa analyzed by SDS-polyacrylamide gel electrophoresis.