This paper presents an intriguing study on the influence of damping oil to the transient response of the displacement output of a flexure-based mechanism when comparing the responses in two cases working in or not in lubrication oil. The mechanism includes two flexure amplifier levers connected by a bar with two flexure hinges creating a structure of flexure four bar linkage. Prior to fabrication, the designed flexure mechanism was evaluated with two models: numerical Ansys model and pseudo rigid body model with Matlab Simulink. The models were used to predict transient response in terms of displacement and stress under viscous damping. Then the results of modeling and simulation were validated by experiments. Both numerical simulations and experimental results show that the output displacement responses including overshoot and response time are significantly reduced when the applying viscous damping of lubrication oil. Specifically, experiments showed that overshoot and response time were (0.272 mm, 0.05 s) when counting viscous damping, in comparison with (0.341 mm, 0.1 s) when not. These findings open a new study-direction in the application of flexure-based mechanisms in different working environments.