Abstract: The simultaneous solution of the generalized Reynolds equation and the motion equation of the journal were involved, transient three-dimensional temperature of oil film and bus hand the changes of the lubrication's viscosity and density with the temperature and pressure were taken into account and then the transient performances of a journal bearing were acquired. The results showed that the axis was fixed in new position and the performance parameters were fixed in new values after plant attenuation, but the needed time had no relation with the magnitude of the shock loads. The moving trail of the axis extended with the shock load's increasing. The temperature of oil film was affected by the heat transfer inertia of the oil film and the bush. Then the minimum film thickness and the maximum film pressure were affected by the temperature variation of the oil film.