〔Abstract〕 Extraction of CP-PGN was processed according to the TCA method, the purity of the final product was verified by treating with the lysozyme. Then the molecular weight, structures and compositions of amino acids of CP-PGN were studied. The animal models of bloodstream infection were established by using carbapenenes producingKlebsiella pneumonia(KPN) andCandida albicans(CAL) to the evaluation of the effect of CP-PGN against bloodstream infection. The lysozyme dissolution experiment verified that the extracted product was peptidoglycan and CP-PGN possessed the characteristics of peptidoglycan. The molecular weight of CP-PGN is 18 774 u, which showed the characteristic peaks of PGN by infrared spectroscopy. The GB/T14965-1994 was used to detect its compositions of amino acids. CP-PGN significantly prolonged the survival time, improved the survival rate of mice and showed different degree of prevention in the animal experiments. All these showed that the extracted product of CP-PGN had the significant preventive and resistant effects on KPN and CAL-induced bloodstream infection.