Abstract: The exact stationary solution for any first order nonlinear dynamic problems excited by Gaussian white noise has been obtained by solving its corresponding FO her- P I anck- Kolmogorov equation. In this paper the relationship between the nonlinear damping force and the transition probability density of velocity response of OLEO damper excited by Gaussian white noise has been obtained, which is based on the exact stationary solution of FPK equation. So we can get the nonlinear damping force parameters by me...