Fundamental-mode Love waves, with period ranging from 2 to 7 sec, were recorded by the dense strong-motion network in Taipei basin, during the June 5, 1994 Nanao earthquake. In the frequency-wavenumber spectra, the Love waves propagating in the direction from the epicenter to the basin were verified to be the principal phases in this period range. Using the interstation surface-wave inversion method, the shallow crustal structure beneath the basin was determined. Results show that the shear-wave velocities of 1 to 4 km deep layers are in the range from 2.1 to 2.4 km/sec. Accordingly, a lateral variation derived within the basin is evident.