A medical electronic endoscope with an outside diameter of 4.5mm was developed for uterine cavity lesions examination without anesthetics. The electronic endoscope, with a flexible head of 270° turning angle and an optical imaging system of 100° field angle, realizes non-blind spot diagnosis. The effective focus length of the optical imaging system is 1.2mm, the depth of field 10–100mm, the maximum field curvature 0.1mm, and the resolution capability of image system 145cycles/mm. CCD image sensor is with a diagonal dimension of 1/10in. and SVGA display model of 500×580 pixels. The illumination system uses the crescent-shaped optical fiber bundle as light transmission and metal halide lamps, high illuminance and high color temperature, as light source. Filter denoise, image enhancement and distortion correction are performed on video image to get a clear, distortionless and high resolution image where blood vessels and tissue morphology of uterine are displayed in real time. The medical electronic endoscope can offer doctors an effective means and reliable bases to early diagnose uterine diseases, especially early-stage malignant tumors.