This invention relates to a bacteriophage MPK6 (deposit number: KCCM 11044P) having a lytic activity to Pseudomonas aeruginosa, or a progeny bacteriophage thereof having a RFLP (Restriction fragment length polymorphism) DNA profile substantially equivalent to the bacteriophage MPK6. The present invention provides a bacteriophage MPK6 or a progeny bacteriophage thereof capable of treating a Pseudomonas aeruginosa infection disease, and suggests an anti-bacterial activity of MPK6 and its progeny bacteriophage using a mammalian and non-mammalian infection model. According to the present invention, the present bacteriophage MPK6 or progeny bacteriophage thereof represents very effective efficacy on treatment of P. aeruginosa-induced peritonitis-sepsis.