Abstract: Using three-dimensional continuous stay cables as objects, the partial differential equations for stay cables with rain-wind-induced vibration are derived and an analytical model for rain-wind-induced vibration of three-dimensional continuous stay cable is developed. In order to simplify the complex problem, the moving of rivulets is assumed to be sinusoidal by experiences, and rivulet balance position and rivulet moving amplitude are also presumed on the basis of wind tunnel test results. With fixed rivulets on the surface of stay cables, classical galloping is firstly studied. The results show that classical galloping occurs at certain conditions. The influences of velocity, rivulet frequency, rivulet position, wind speed profile and cable damping to rain-wind-induced vibration are particularly investigated. It is found that rain-wind-induced vibration depends deeply on wind velocity, rivulet frequency, rivulet position and cable damping.