Abstract: According to problems that current high dynamic range（HDR） image generation methods require high acquisition equipment and don＇t apply to the acquisition of dynamic scenes, a generation method of HDR image from a single LDR image based on Retinex enhancement is proposed. Firstly, a single LDR image is mapped to generate multiple different exposure images based on Retinex algorithm. Secondly, the weight of each image is computed by combining four measurement factors, such as contrast and saturation of the image. Finally, HDR image is generated by using the pyramid decomposition. Experimental results on multiple images show that the HDR image generated by the proposed method has a clearer texture and a better human visual effects.