Atomic force microscope(AFM) was used to observe the effects of modifier on surface morphology of asphalt, including the original asphalt as control, un aged and aged SBS modified asphalt, un aged and aged Sasobit modified asphalt. It shows that there exists bee typed structure in the asphalt and the number and area proportion of bee typed structure in SBS modified asphalt are less than that in the control and its structure is more rough. Bee typed structure of Sasobit modified asphalt turns to be slender and few. Bee typed structure of these asphalts will be bigger and more at aging and it will be rougher. SBS modifier can improve the high temperature stability and short term aging resistance of the asphalt. Sasobit modifier can change the crystal structure distribution of the asphalt, which turns that it can improve the aging resistance of asphalt too. The change of average area of bee typed structure can be used to evaluate the aging characters of asphalt well.