In the 1st report, a method to identify the characteristic matrices from the response of the vibration system was proposed, and the characteristic matrices of two beams were identified using the transfer function including some experimental error in the 2nd report. In this paper, two new methods to identify the characteristic matrices are proposed. One is the method that the characteristic matrices are identified applying the conception of the robust statistics. In this method, the weight of the measured results including large experimental error is made small or neglected. In the other method, it is assumed that the statistical distribution of experimental error is the normal distribution, and the characteristic matrices are identified according to the statistical consideration. The characteristic matrices of a cantilever beam and a free-free beam are identified from the measured transfer function by the previously proposed method and the newly proposed methods. The vibration of connected beam is calculated by combining the identified characteristic matrices and compared with the experimental results. And it is found that a most accurate method is the method applying the conception of the robust statistics, and it is considered that the method is practical and useful.