The effects of growth temperature and a carbon source on the expression of $eta$-galactosidase gene of Lactococcus lactis ssp. lactis ATCC 7962 (L. lactis 7962) were investigated. At $25^{circ}C$, L. lactis 7962 had a higher $eta$-galactosidase activity than cells grown at $30^{circ}C$ or $37^{circ}C$, although cells grew most quickly at $37^{circ}C$ The highest $eta$-galactosidase activity was observed in cells grown in M17 with lactose (l %) followed by cells grown in a galactose (1 %) medium. L. lactis 7962 exhibited the minimum $eta$-galactosidase activity in glucose media, indicating catabolite repression. When the cellular levels of $eta$-galactosidase mRNA were examined using slot blot hybridization, no significant differences were observed between cells grown at $25^{circ}C$ and cells at $30^{circ}C$ or $37^{circ}C$ in the same media. This suggests that the quantity of $eta$-galactosidase mRNA may not be the reason for the higher $eta$-galactosidase activities of L. lactis 7962 at $25^{circ}C$ The level of ccpA (Catabolite Control Protein) transcript remained almost constant during the exponential growth phase irrespective of a carbon sourse.