Rotor in small-medium induction motor has been usually manufactured by aluminum diecasting. In order to improve the efficiency of induction motors, newly developed Cu-Ca alloys have been investigated. The electrical conductivity in the Cu alloys containing Ca less than $1.0wt\%$ was higher than $80\%$ IACS. Cu-Ca alloy is desirable for the thixoforming process because it has wide semi-solid range over $150^{circ}C$. In this study, Cu-rotor with thixoforming process was developed to replace the conventional aluminum diecasting rotor. Analysis was performed for the microstructure of thixoforming rotor. Effect of incomplete filling on the efficiency of induction motor was discussed.