A method of treating an on-press developable lithographic printing plate with a treating solution after imagewise exposure and before on-press development is described. The plate comprises on a substrate a photosensitive layer developable with ink and/or fountain solution and capable of hardening upon exposure to a radiation. The plate is imagewise exposed with a radiation, overall treated with a treating solution to cause at least one chemical or physical change in the photosensitive layer or on the substrate surface, and then on-press developed with ink and/or fountain solution. Such a treatment allows improvement on the performance of the imagewise exposed plate by, for example, improving the white light stability, forming visible imaging, increasing the hydrophilicity of the substrate, or increasing the developability of the photosensitive layer.