Provided is a novel bacteriophage ΦCJ19 (KCCM11361P). In addition, the present invention relates to an antibacterial composition including the bacteriophage ΦCJ19 (KCCM11361P) as an active ingredient. Further, the present invention is a method of preventing and/or treating infectious diseases by enterotoxigenic Escherichia coli in animals except for humans using the bacteriophage ΦCJ19 (KCCM11361P) or the antibacterial composition containing the bacteriophage ΦCJ19(KCCM11361P) as an active ingredient.