This paper presents experimental research to determine the influence of cutting parameters on surface roughness when fine milling of spiral bevel gear. Three parameters of the cutting parameters investigated in this study include cutting velocity, feed rate and depth of cut. The test material used in this study is 20XM steel. The cutting tool used in this study is a hard alloy coated with CVD Ti (C, N)-Al2O3-TiN. The testing process were carried out with 15 tests in the form of Box-Behnken planning. The results of analysis of testing data have determined that the cutting velocity is the parameter that has the most influence on the surface roughness of teeth, followed by the influence of the feed rate. The depth of cut has a negligible influence on the surface roughness of teeth. The interaction influence of the parameters on teeth surface roughness was also discussed in this study. This study has also proposed a surface roughness model - using this model to predict surface roughness and proposing development directions for further studies