Abstract: A system of simultaneous eqations consisting of the Reynolds eqations of pressure perturbations in consideration of dynamic deformation and the deformation eqations of sliding bearings was derived in complex form. The formulae for the dynamic promperties and stability were also derived. A reduced flexibility matrix was 'conveniently obtained using SAP 5 program. The pressure perturbations, bearing dynamic properties and stability in cosideration of dynamic deformation in typical cases were calculated, the results were analyzed and compared with those only consider the static deformation. It was noticed that the difference was significant under certain conditions, themrefore the importance of dynamic deformation became evident. Masurements of a nylon bearing and a bronze bearing were made and the results confirm the theoretical calculation qualitatively.