This paper is a study on simulation based design technique for passive control system to reduce the pitch motion of the mast top caused by the reach operation of electric reach trucks. Mast vibration characteristics have been analyzed using a mast vibration model by RecurDyn. Hydraulic reach model and hydraulic vibration reduction system model by AMESim were used in order to optimize the detailed specifications of the passive-controlled vibration reduction system. Finally, a test vehicle equipped with the system showed a significant reduction in the mast top vibration.