It is an object of the present invention to provide a clad glass composition for graded-index rod lens for covering, during manufacturing, a preform glass composition lens of a graded-index rod lens that does not include PbO, in which the composition substantially does not include PbO, and expressed in mol % includes SiO.sub.2: 45 to 65, Na.sub.2O: 3 to 30, K.sub.2O: 0 to 10, MgO: 0 to 15, BaO: 0 to 20, where Na.sub.2O+K.sub.2O: 3 to 35 and MgO+BaO: 0 to 25, and furthermore includes B.sub.2O.sub.3: 0 to 15, ZnO: 0 to 10, TiO.sub.2: 0 to 10, Y.sub.2O.sub.3: 0 to 7, ZrO.sub.2: 0 to 7, Nb.sub.2O.sub.5: 0 to 7, In.sub.2O.sub.3: 0 to 7, La.sub.2O.sub.3: 0 to 7, Ta.sub.2O.sub.5: 0 to 10, where B.sub.2O.sub.3+ZnO+TiO.sub.2+Y.sub.2O.sub.3+ZrO.sub.2+Nb.sub.2O.sub.5+In.- sub.2O.sub.3+La.sub.2to 20, and a content of at least one of TiO.sub.2 and La.sub.2O.sub.3 is substantially 0 mol %.