A testing method and testing system for a semiconductor element are provided. The method includes following steps. A level of a testing electrostatic discharge (ESD) voltage is determined. A plurality of sample components is provided. The testing ESD voltage is imposed on the sample components for testing ESD decay rates of the sample components. ESD withstand voltages of the sample components are detected. The relation between the ESD withstand voltages and the electrostatic discharge rates are recorded to a database. The testing ESD voltage is imposed on the semiconductor element for testing an ESD decay rate of the semiconductor element. The database is looked up according to the ESD decay rate of the semiconductor element to determine an ESD withstand voltage of the semiconductor element.