A method of determining suitability of correction for a control logic of a selective catalytic reduction (SCR) catalyst, may include determining a suitability function of the correction based on a previous error and a current error when the correction has been performed, determining a suitability coefficient based on the suitability function of the correction, determining whether the correction may be suitable based on the number of corrections and the suitability coefficient, and resetting the control logic when the correction may be not suitable.