To provide a resin composition which is suitable for use as a material for optical parts and disk substrates and molded products thereof. The resin composition comprises: (1) 10 to 90 wt % of a first hydrogenated, polymerized styrene which contains a hydrogenated, polymerized styrene unit in an amount of more than 95 wt % and 99.99 wt % or less and has a weight average molecular weight of 30,000 to 300,000; and (2) 10 to 90 wt % of a second hydrogenated, polymerized styrene which contains a hydrogenated, polymerized styrene unit in an amount of 60 to 95 wt % and has a weight average molecular weight of 30,000 to 200,000, “wt %” being based on 100 wt % of the total of the first hydrogenated, polymerized styrene and the second hydrogenated, polymerized styrene.