In the field of structural identification, Kalman filter and Particle filter have been one of the most widely used tools. These are called parameter identification or data assimilation methods and are methods for updating simulation models one by one while introducing measurement data to the simulation model. In the updating process, the dynamic characteristics of the observed structure such as the stiffness and damping properties are estimated. However, in order to ensure the identification accuracy, it is extremely important to set the process noise. This study attempts to identify the structural parameter for the purpose of damage quantification by using merging particle filter. The performance of the proposed system is discussed through numerical simulations and a shaking table test.