Based on the double Euler Bernoulli beam theory, two dynamic models were established to evaluate the vibration isolation performances of the floating slab track system with continuous cast-in-place slabs and discontinuous pre-cast slabs. By using Fourier transformation method, differential equations of two models were solved in the wavenumber-frequency domain for dispersion analysis. The contour integration method was used to convert the dynamic responses of the track systems from the wavenumber-frequency domain in the space-time domain. The result demonstrates that the cut-off frequencies of the track with cast-in-place slabs are slightly higher than that of the pre-cast slabs. The curvature of dis p ersion curve in floating slab is directly proportional to bending stiffness, and the curvature of cast-in-place slab is approximately equal to zero. The effect on increasing train speed is the amplifying dynamic response of the track. For t he train speed below 20 m／s, it has no obvious effect on dynamic response of cast-in-place slab but marked effect on the pre-cast slabs. The floating slab track with pre-cast slabs produces a larger resonance response than that with cast -in-place slabs because of the infection due to standing wave occurred in pre-cast slabs. When the excitation frequency keeps away from the cut-off frequency, the dynamic response of the pre cast slabs attenuates more rapidly and approximately equals the response of the cast-inplace slabs under the high-frequency excitation.