A compact image taking lens system with a lens-surfaced prism of the present invention comprises a prism, an aperture stop, a first lens element, a second lens element, reflecting mirror surface, and image surface, optionally an infrared cut-off filter. By introducing a lens-surfaced prism, the compact image taking lens system with a lens-surfaced prism of the present invention has many advantages over the prior arts in the field of invention, such as compactness in thickness, small number of optical elements, high performance of optical quality, enough space for optional elements such as an infrared cut-off filter and diversity in optical geometries.