In order to study the surface roughness of titanium alloy by micro-textured ball-nosed end mill within milling，based on orthogonal test，the experiment of milling titanium alloy with micro-textured ball end milling cutter was carried out. The variation regularity between the texture parameters and the surface roughness was obtained and the mechanism was analyzed. The influence of various factors on the surface roughness is determined by the range analysis method. Based on the principle of regression analysis，the predictive model of surface roughness was established. The statistical test results show that the prediction model of surface roughness is significant. The predicted values of the surface roughness were compared with the experimental observations，which confirmed the reliability of the model.