This paper is concerned with the vibration analysis of a liquid-filled pipe system,which extends the frequency domain analysis of the fluid–structure interaction from single pipe to a pipe system with multi-pipe sections using transfer matrix method.Taking into account all the three major coupling mechanisms,namely the friction coupling,Poisson coupling and junction coupling,the proposed method can be used to analyze the free vibration and the forced vibration of a pipe system with multi-pipe sections subjected to various kinds of external excitations.The transform matrix,impedance matrix and frequency equation in frequency domain are also presented and discussed.Numerical examples are presented to illustrate the application of the proposed method,which shows how the natural frequencies and mode shapes change with the radius and materials of the pipe system.