A new method to measure electron temperature and electron energy distribution function by an emissive probe has been proposed. The method is based on measurement of the functional relationship between the floating potential and the heating voltage of emissive probe. From the measured data of the floating potential change as a function of the heating voltage, the electron temperature could be determined by comparing with the theoretical curve obtained under the assumption of Maxwellian distribution. The electron temperatures obtained by the present method were consistent with those measured by the rf-compensated Langmuir probe within the error.