In this paper, we proposed a contrast-enhanced homemade spectral domain optical coherence tomography (SD-OCT) method for monitoring of brain microcirculation. We used the polyethylene glycol (PEG)-ylated gold nanorods (GNRs) as a contrast-enhanced agent, obtained clearly 2D and 3D OCT images of blood vessels and dynamic changes of probes in mouse blood vessels. Owing to high scattering of the PEG-GNRs, more tiny blood vessels can be imaged and the OCT signal can be enhanced by 5.87 dB after injection of PEG-GNRs for 20 min, the enhancement then declined gradually for 60 min. Our results demonstrate an effective technique for the enhanced imaging of blood vessels in vivo, especially for studies of the brain microcirculation, which could be serviced for disease mechanism research and therapeutic drug monitoring.