Abstract: OBJECTIVE Trionycis Carapax Peptide HGRFG liposome and its long-circulating liposome modified by polyethylene glycol(PEG) were prepared to study the distribution of modified liposomes and unmodified liposomes in animals. METHODS The BLB/c nude mouse fluorescence in vivo imaging experiment was used to study the distribution and metabolism of liposomes in vivo. The pharmacokinetic experiments were used to investigate the retention time of two different drug-coated liposomes in plasma. RESULTS Two different drug-coated liposomes were widely distributed in experimental animals. The retention time of fluorescence disappearance in nude mice of PEG-modified long-circulating liposome-packaging group was significantly higher than that in unmodified liposome-containing drug group. The retention time of the drug in the unmodified liposome group was significantly lower than that in the PEG-modified group. CONCLUSION It has been experimentally confirmed that long-circulating liposomes modified by PEG can prolong the storage time of the drug in experimental animals and prolong the half-life of the drug.