Abstract: It is necessary that developing dynamic performance model to analysis effect on suspension by mount. The key step is developing the right math model based on experiment, bilinear restoring force model is suitable for mount hysteretic curve, the force of restitution is the summation of linear rigidity force, third order rigidity force, linear damping force and bilinear restoring force, the coefficients are identified by energy method. The curves of coefficients via frequencies and amplitudes are done by calculating the test data, frequency and amplitude effect on coefficients is also mentioned. Damping coefficient is decreasing when vibration frequency was increased; rigidity linear coefficient is increased and third order coefficient is decreasing when vibration amplitude was decreasing.