A fabrication method of a stacked chip structure is provided. Firstly, a first conductive layer is formed on a first surface of a wafer. Afterwards, a first patterned polymer layer is formed on the first conductive layer, and a second patterned polymer layer is formed on a second surface of the wafer. Next, a second conductive layer is electroplated on the first conductive layer and is heated to form a number of solder bumps. After that, the wafers are stacked on a substrate structure. The first patterned polymer layer disposed on a first wafer of the wafers is correspondingly connected to the second patterned polymer layer on a second wafer of the wafers. The present invention is suitable for the stacked chip structure connected by the fine-pitch solder bumps. Besides, the fabrication of the present invention is relatively simplified.