THE PRESENT INVENTION PROVIDES A METHOD FOR PRODUCING FERMENTED MILK, THE METHOD EMPLOYING A LACTIC ACID BACTERIUM CAPABLE OF IMPROVING PROLIFERATIVE PROPERTIES OF BIFIDOBACTERIUM, AND A FERMENTED MILK PREPARED BY THE PRODUCTION METHOD. SPECIFICALLY, THE PRESENT INVENTION PROVIDES A METHOD FOR PRODUCING A FERMENTED MILK, INCLUDING FERMENTING A FERMENTATION BASE USING BOTH LACTOCOCCUS LACTIS STRAIN HAVING CELL WALL-ENVELOPED PROTEINASE, PRTP, AND BACTERIA BELONGING TO A GENUS BIFIDOBACTERIUM, AND A FERMENTED MILK PREPARED BY THE PRODUCTION METHOD.