The invention provides an object lens for endoscope, which not only ensures the long rear cut-off distance, but also excellently corrects the lateral chromatic aberration, wherein a negative first lens (L1) having concave surface toward image side, a first joint lens (L23) formed by jointing a second lens and a third lens, one positive and one negative, a positive fourth lens (L4) having the side with large absolute value of plane or curvature radius toward object side, and a second joint lens (L56) with integral positive refractive force formed by sequentially jointing a positive fifth lens and a negative sixth lens from the object side are arranged in sequence from the object side, which fulfill the conditions (1), (2): (formula), wherein, f is focus Bf is the rear cut-off distance v5 is the abbe number of the fifth lens the v6 is the abbe number of the sixth lens RA is the curvature radius of the joint surface of the second joint lens d6 is the central thickness of the sixth lens n6 is the refractive rate of the sixth lens.
