This study examined the effect of medicinal herbs on the growth of 3 strains of lactic starter cultures in a MRS broth by adding a 0, 1, 3, 5, and 10% water extract. The pH, titratable acidity and OD of lactic acid bacteria were investigated in order to obtain fundamental knowledge for the development a new product, box thorn yogurt. In the case of adding the Acanthopanax sessiliflorum Seeman water extract, Streptococcus thermophilus was largely activated by the addition of the 5% extract. The growth of Lactobacillus acidophilus was activated by the extracts but it was depressed by the addition of the 3% Acanthopanax sessiliflorum Seeman water extract. Compared with the control, the growth of Bifidobacterium longum was largely activated by the addition of the 10% extract but it was depressed by the addition of the 5% Acanthopanax sessiliflorum Seeman water extract.