The characteristics of tire/road interaction noise are mainly determined by the tread pattern of a tire. It is known that the impact force at leading edge between tire and road is greatly influential to the pattern noise. This study is concerned with prediction of pattern noise of tire with rectangular patterns by using the measured impact force at leading edge. The normal pressure at the leading edge between tread block and flat road is measured in both static and dynamic load conditions. By regressing the measured data, the pressure distribution function at contact edge is obtained and also the impact force variation is calculated. From the force variation, the impact force spectrum is calculated by using the fast Fourier transform. Hertzian impact theory and gear analogy theory are employed to approximately obtain the maximum force magnitude and impact duration time at high vehicle speeds. The longitudinal quadrupole model is applied to simulate the noise spectrum from the force spectrum. Theoretically predicted force and noise spectra are compared with the measured noise spectrum in a semi-anechoic chamber with the chassis dynamometer. Predicted and measured spectra agree reasonably well in view point of fundamental frequency and its harmonics.