An optical lens assembly for image taking, sequentially arranged from an object side to an image side, comprises: the first lens element with refractive power, the second lens element with positive refractive power, the third lens element with negative refractive power having a concave object-side surface and a convex image-side surface, the fourth lens element with positive refractive power having a convex object-side surface. The optical lens assembly further comprises a stop and an image sensor on an image plane. Each of the third and the fourth lens elements can have at least one aspherical surface. When the optical lens assembly utilizes the thickness conditions provided in the present invention, along with a favorable entrance pupil diameter ratio, fine aberration corrections, wide-angle of view, and functionalities for common image pickup cameras or those used with infrared settings can be achieved.