The objective of the literature is to investigate the influence of micro-arc grooves on the surfaces of the sliding tribopairs by plain pads to hydrodynamic lubrication. This is accomplished by the CFD-approach (computational fluid dynamic approach) where the momentum and continuity equations are solved separately, laminar model and SIMPLE algorithm in theory of Control Volume Method are adopted, and the rheology is assumed to be Newtonian. For various widths and depths of micro arc-grooves, the load supporting capacity of oil-film is calculated in the form of a net total force and static pressure, the friction is compared by the stress of smooth wall, and the dynamical pressure of the upper walls is shown. It will be found that width has more influences than depths to hydrodynamic lubrication, and relative parameters change monotonously with the depth of arc groove. Moreover, given primary film thickness as 6μm, within physically reasonable range of the parameters (depth and width of groove), i.e. in addition to w=40μm, hp=5μm~15μm, the effect of texturing arc-grooves on improvement of tribological properties will be conspicuous.