An over-current protection device comprises at least one PTC component, at least one thermal dissipation layer, at least one adhesive layer and at least two isolation layers, wherein the PTC component is formed by interposing a PTC material between two electrode layers. The at least one adhesive layer as a thermal conductive medium is interposed between the PTC component and at least one thermal dissipation layer to combine them. The at least two isolation layers separate the thermal dissipation layer, adhesive layer and electrode layers into two electrical independent portions.