Purpose: The purpose of this study was to investigate the in vivo formation process of laser-induced choroidal neovasculation (CNV) in rat using high-resolution spectral-domain optical coherence tomography (SD-OCT) and compare the results with that of histological methods.Methods: The Norway Brown rats (n=60, 6-8w of age) received 532-nm diode laser photocoagulation.In vivo SD-OCT and Fluorescein angiography (FA)were performed at 2, 5, 7, 14 and 21 days post laser application.At each same time points, hematoxylin and eosin (H&E) and immunohistochemistry of CD31, pVEGFR2 were conducted to observe the CNV in vitro.Choroidal flatmounts preparation were observed by confocal laser scanning microscope (CLSM) and scanning electron microscope (SEM).Results: The longitudinal morphological changes of laser induced CNV could be monitored by SD-OCT.CNV reached its maximal size at day 7 and reduced gradually since day 14.FA showed similar dynamic changes of leakage.The thickness of CNV assessed by SD-OCT were consistent with H&E stained section in each time point.CLSM and SEM examination revealed the details of fibrovascular membrane.Expression of CD31 and pVEGFR2 supported the results obtained from SD-OCT and histological methods.Conclusions: SD-OCT is a convenient and reliable tool to image the CNV formation process and quantify the lesion size in vivo.