A new way, which is used to analysis the path contribution, is presented for the vibration transfer path systems considering the interact of vibration source, transfer path and receiver. It is that the path contribution is evaluated using the path transfer probability. According to the dynamic characteristics of vibration systems, the new concept of path transfer probability is given. Based on the generalized probabilistic perturbation method and the reliability theory, the computational approach for path transfer probability with uncertain physics and geometry factors in time range are presented. The transfer probability of vibration transfer path systems with translational and rotational motions is analyzed and calculated via a numerical example, which shows that the proposed method is feasible.