Spring Operating Mechanism(SOM) of circuit breakers in High voltage class has characteristics of high power, high speed and long-term waiting time. Thus, the mechanical dynamic behavior of circuit breaker is significantly affected by these kinds of the characteristics. In the case of a dashpot system in the SOM, it has been used to reduce the impact force at the end of mechanical operation especially. Also this system has influenced the electrical and mechanical safety performance. Therefore, it is significantly important to predict and evaluate the damping characteristic of the SOM in the initial development stage of the circuit breaker. In this paper, the developed 1D simulation model for dashpot with spring operating mechanism is introduced and correlation results between analysis and test are reviewed.