In this paper, theimpact of the orders of fractional corrrelator on the energy distribution of thecorrelation plane is analyzed theoretically, and then the performance of fractionalcorrelator for scale distortion-invariant pattern recognition is discussed deeply bynumerical method based on the matched-filtering configuration. A comparison is made withthe conventional correlation that shows the fractional correlation possesses more powerfulcapability of scale distortion-invariant pattern recognition than that of the conventionalcorrelation.