Abstract: Polyethylene glycol(PEG)with good hydrophilicity and flexibility can improve pharmacokinetic and pharmacodynamic properties of the nano-preparation, so PEG modification in the surface of nano-preparation can increase the in vivo residence time and concentration of drugs. At present, the targeted nano-preparation with PEG modification has become a research hotspot in the field of pharmaceutics. In this paper, the physical and chemical methods of PEG modification in targeted nano-preparation was summarized, which includes physically inserting PEG-lipid derivatives in nanostructure of targeted nano-preparation or modifying PEG with targeted nano-preparation. In addition, the influence of PEG parameters(molecular mass, modified density and spatial conformation)on properties of targeted nano-preparation was also discussed, which is important to preferably structure PEGylated targeted nano-preparation.