Abstract:In order to determine the influence of various starter strains and ripening periods on the formation of antibacterial and antioxidant materials in water soluble extracts for Mozzarella cheese, activities of antibacterial for E.coli, Bacillus subtilis, Staphylococcus aureus, yeast and mould were detected by filter paper dispersion method. DPPH scavenging rate, reducing power in vitro and the antioxidant in vivo were also investigated. The results indicated: the antibacterial and antioxidant property of extracts changes with strains and ripening stages exhibited stronger inhibition against bacteria than fungi, extracts of cheese with AB+LH ripening 60 days showed higher bacterial inhibition than the other cheeses, cheese with AB+LA ripening 40 days demonstrated highest scavenging rate of DPPH and the inhibition value was 67.76%, cheese with AB ripening 50 days displayed greatest reducing power of 1.23, the extracts also have antioxidant in vivo.