A lamination process and structure of a high layout density substrate is disclosed. The lamination process comprises the following steps. First of all, a plurality of laminating layers are individually formed, wherein each laminating layer has a first dielectric layer, a plurality of first vias and a patterned conducting layer. Next, a bottom layer having a second dielectric layer and a plurality of second vias is formed. Then, the laminating layers and the bottom layer are stacked. Finally, the laminating layers and the bottom layer are laminated simultaneously to form a multiplayer substrate at one time.