Abstract: It is essential to understand how the guided waves travel in benthal pipes in order to monitor/inspect their health statues. In this paper, the propagation characteristics of longitudinal guided waves in oil-filled and with viscoelastic coating pipes under water loading have been investigated by a global matrix method. The displacement and stress distribution in pipes have been numerically calculated. The dispersion curves and wave structure such as α mode and L(0,4) mode have been presented, through which the propagation mechanism for the longitudinal guided wave traveling in the pipe is demonstrated. The result can be used to support the design and implementation of damage detection schemes for pipe-like structures.