A lens module with an optical axis passing therethrough from an object side to an image side includes a lens housing and two lenses disposed in the lens housing. The first lens has a first refactive portion and a first positioning portion encircling the first refractive portion. A first mating structure is formed on the image side surface of the first positioning portion and molded with the first refractive portion as a single integral. The second lens has a second refractive portion and a second positioning portion encircling the second refractive portion. A second mating structure is formed on the object side surface of the second positioning portion and molded with the second refractive portion as a single integral. The mating structures are engaged to align the lenses along the optical axis, and the refractive portions are coaxial with each other and have the axis as the optical axis.