A 2 DOF nonlinear dynamic model of the automotive wiper system based on the theory of stick slip vibration was established. Bifurcation diagram and trajectories on the phase plane were adopted to confirm the pervasive phenomenon of stick slip vibration and to study its characteristics under various wiping velocities through numerical computation. Spatial and temporal distribution of stick slip vibration was analyzed by means of time histories and contour maps. Quantitative index of duty ratio of stick motion and quantity statistics of scraping were introduced to evaluate the wiping effect. The results indicate that the occurring of stick slip vibration and its characteristics under various wiping velocities possess complicated nonlinearity. The nonlinear stick slip vibration vanishes only when the nominal wiping velocity is higher than 0.725 m?s-1. Increasing the wiping velocity benefits the control of stick slip vibration and reduces the adverse influence on wiping effect caused by the heterogeneous distribution of scrapings.