The optical and analytical modeling of a line-scan optical coherence tomography (LS-OCT) system for high-speed three-dimensional (3D) endoscopic imaging is reported. To avoid complex lens system and image distortion error, an off-axis cylindrical mirror is used for focusing the line illumination on the sample surface and a micro mirror scanner is integrated with the proposed configuration for transverse scanning. The beams are swept on the cylindrical mirror by the micro mirror rotation and finally focused on the sample surface for transverse scanning. A 2mm by 3.2mm en-face scanning is configured with a 2mm focused line and ±3° scanning mirror rotation. The proposed configuration also has the capability of dynamic focusing by the movement of the cylindrical mirror without changing the transverse resolution. The cylindrical mirror enhances the image quality by reducing the aberration. The system is capable of real-time 3D imaging with 5μm and 10 μm axial and transverse resolutions, respectively.© (2009) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.