n order to predict the characteristics of machined surface texture in ballnose milling, the surface topography simulation model aiming at geometric characteristics of ballnose end mill was established. Main factors affecting the surface texture were analyzed. According to different mix of feed rate per tooth fz, path interval p and constant phase difference Δθ, the influence rule of distribution and direction of machined surface texture was investigated through simulation and experiment. The result shows that the surface texture forms are different for the different processing parameters, different phase difference leads to the transformation of distribution and direction of surface texture for the same processing parameters, and the machined surface texture is in consistent with the simulation result, which means that the study can provide the basis for the prediction of surface texture.