In this study, the experimental of accelerated aging in induction motor insulation is done in a loaded state with high humidity influence and under effects of contaminant. The method used to evaluate the condition of the motor is polarization index (PI), oscillatory response test (surge test) and LCR measurement. PI is used to determine the value of polarization index and custody coil insulation via measured four direct current during the test. Oscillatory response test used to determine differences in the quality of the coil insulation based on the response to the wave oscillation with error area ratio (EAR) method. While the LCR measurement is used to detect the value of inductance, capacitance and resistance arising from the influence of humidity and contaminant in the stator's coil. Furthermore, the output PI variable and oscillation response test and LCR measurement compared to getting the tendency chart damage. Based on test results, EAR method is faster to detect decrease coil insulation in the second test by 30.5 %. Meanwhile, the new PI value was changes in its value in the fourth test. While the LCR value is not significant.