The capacitor induction motor (CRM) is widely used in many types of equipment because of their robustness and simplicity of structure, low cost, and easy maintenance. However, the resultant flux wave in the air gap due to forward and backward magnetic fields produces dominant electromagnetic vibration and noise, depending on the slot combination. Although the electromagnetic vibration caused by these motors under the no-load condition has been studied for many years, and the fundamental factors thereof have been analyzed extensively, the electromagnetic vibration under load conditions has yet to be analyzed in sufficient detail. In this paper, the causes and the characteristics of the electromagnetic vibration of CRM under load conditions are investigated based on experimental results.