Short-period micro tremor array observation is conducted at five sites in the Tokyo Metropolitan area of Japan. The Fourier spectra of horizontal and vertical components show variations in time, but their ratio is stable for different time instants. The characteristics of the amplitude ratio are similar to that of Rayleigh wave and the period correspond to the peak ratio correspond to the predominant period of the sites for shear wave propagation. A parametric study for two-layered models reveals that the peaks for Rayleigh wave and shear wave are close for the ground having large impedance ratio. The F-K spectrum analysis using vertical components obtained the phase velocity close to the dispersion curve for the Rayleigh wave
