In this work, the thiolpolyethylene glycol (PEG) modified gold nanorods (Au NR) were prepared by a facile hydrothermal synthesis method. The nanomaterial has good light absorption property in near infrared region, and has the potential as an excellent photoacoustic contrast agent. The characterizations of the morphology, structure, basic optical property and photoacoustic imaging effect et al have been investigated by TEM and UVVIS absorption spectrum. The experimental results show that the response of in vitro photoacoustic signals increases linearly with the increase of material concentration. The biocompatibility of gold nanorods has been improved via PEG modification. The imaging effect of PEGmodified gold nanorods on the cerebral vessels cortex of mouse has been enhanced. The results show that the PEGmodified gold nanorod materials have great application prospects in the field of photoacoustic imaging.