The present invention relates to a method of making a plasma display panel, and more specifically, a method of forming a dielectric layer on an upper substrate of a plasma display panel. According to first embodiment of the present invention, a method of forming a dielectric layer on an upper substrate of a plasma display panel, comprises steps of: forming a plurality of sustain electrodes on the upper substrate, and bus electrodes on the sustain electrodes; forming an electrode discoloration prevention layer which envelops said sustain electrodes and said bus electrodes, said electrode discoloration prevention layer including a green sheet by first casting; forming a penetration rate enhancement layer on the electrode discoloration prevention layer, said penetration rate enhancement layer including a green sheet by second casting.