A method to determine all 16 dynamic coefficients of two journal bearings from impulse responses is described. From the transfer functions of the displacements to the excitation forces, all 16 coefficients of two journal bearings can be obtained based on least-squares estimation. Computer simulation verifies that the experimentally identified coefficients approximate well the measured rotor-bearing dynamic characteristics in both time and frequency domains. Oil whirl phenomena were found in the experiments. The whirling frequencies correlate well with the values predicted from the estimated bearing coefficients and agree very well with the linear stability theory. Detailed formulae, experimental procedures, measured signals and estimated bearing coefficients are presented. © 1997 Elsevier Science S.A.