Based on the tidal stress on the fracture, the amplitude ratio and phase shift models of fracture fluid pressure (FFP) response to tide generating height (TGH) are presented in undrained single fracture and multiple fractures. The response model is applied to calculate the fluid pressure amplitude ratio and phase shift with fracture occurrence, and to investigate the response of FFP amplitude ratio and phase shift to the changes of the rock elastic parameters (A, μ) and fracture Skempton coefficient ( B). The results show that the FFP-TGH's amplitude ratio of M2 and Ol waves increases with the fracture angle ( DIP) , with the phase shift at ±165°~ ±180°in DIP ＜15°and ±10°～0°in DIP ＞ 15°o and opposite symbols for M2 and O1 waves. The FFP amplitude ratio responses linearly to the changes of rock elastic constants (λ, μ) and fracture Skempton coefficient (B) , but phase shifts are almost free from the impact of media elastic parameter changes.