The structural $eta$-galactosidase gene (lacZ) from Lactococcus lactis ssp. lactis 7962 was cloned into plamid vector pKF18, which was designated as pKF-gal. Expression of the lacZ from L. lactis 7962 was found to be higher when cells were grown at 3$0^{circ}C$ than 37$^{circ}C$. Maximum $eta$-galactosidase activity was obtained when E. coli/pKF-gal was cultivated for 6hr at 3$0^{circ}C$ and for 3hr at 37$^{circ}C$, and L. lactis 7962 was grown for 8hr at 3$0^{circ}C$. Enzyme induction was achieved by the addition of lactose, galactose, or lactose+IPTG to growing culture. The addition of glucose had no effect on enzyme induction.