A solar cell testing system including a lower electrode, a solar cell, an encapsulation material, a sodium-containing template, an upper electrode, a voltage source and a measuring circuit is provided. The solar cell is disposed on the lower electrode. The encapsulation material is disposed on the solar cell. The sodium-containing template is disposed on the encapsulation material, wherein the sodium-containing template has a sodium ion content ranging between 9-39%. The upper electrode is disposed on the sodium-containing template. The voltage source is connected between the upper electrode and the lower electrode. The measuring circuit is connected between the solar cell and the lower electrode for measuring a shunt resistance of the solar cell.