The article presents the problem of vibration stability of thin-walled curved pipes under internal pulsating pressure. On the basis of semi-momentless theory of anisotropic laminated shells and Lagrange’s equation, a connected system of homogeneous differential equations with periodic rates of stiffness has been developed. As a particular case, the resolving equations describe the parametric vibrations of a straight composite pipe and free vibrations of a cantilever beam. By means of the small parameter method, the calculation of boundaries of dynamic instability region has been done. There has been analyzed the dependency of disposition of regions of the main simple and combination parametric resonances on the constant pressure component, as well as on the structural, geometric factors and damping.