To explore the influence of roundness and cylindricity errors of journal on the lubrication performance of bearing,the model of the radial sliding bearing with roundness and cylindricity errors was established.The expression of liquid film thickness equation considering the integrated error of the bearing was deduced.The influence of roundness and the cylindricity errors on the lubrication performance and loadcarrying capacity of the bearing were studied respectively.The results show that roundness and cylindricity errors can lead to degradation of liquid film lubrication performance of bearing,result in periodical fluctuation of loadcarrying capacity and friction,and furthermore affect the rotation precision of bearing and axial stability.Under heavy loading conditions,the roundness and cylindricity errors have a more significant influence on the lubrication performance of bearing,which can even lead to the rupture of the liquid film and the failure of the bearing.