Abstract: In this study,two samples of ring die forming channel were used to measure and obtain data of their surface morphology with roughness meter,and then the fractal dimension D and fractal feature G were calculated using Yardstick method,and lastly a fractal prediction model of sliding frictional force against the interior surface of forming channel was built based on classical contact mechanics and M-B fractal model. Numerical simulation as well as friction-wear test was conducted to verify the accuracy of the model. The result showed that:When interior surface roughness Raof forming channel is 3.428 μm（45#）,D is 1.373 and G is 1.55×10^-6m. When Rais4.002 μm（40Cr）,D is 1.359 and G is 0.82×10^-6m. Along with the increasing Ar,F increased while FDdecreased. When Ar＜ Arc,the slope of F was larger,which means the frictional force increased more rapidly,and the larger slope of FDrepresents rapidly decreasing unit frictional force. When Ar＞ Arc,F became smaller,which means the increase of frictional force became slower,and the smaller slope of FDrepresents slower decrease of unit frictional force. The experiment data verified that the simulation value is larger than the test value,with the increase of true contact area,the simulation value of frictional force F approximates test value,therefore an overall good simulation result could be achieved by the fractal prediction model of frictional force.