Abstract:The casting molding with a small dish container was used which for prepare the softening point test disk used as the microscopic observation sample. Then the effects of the samples flatness and magnification on obtaining a good and true microscopic phase image of the modifier were investigated. Based on this, the microscopic phases of both bitumen samples modified by SBS with different storage durations as designed in the experiments and samples produced by different manufacturers were observed. In addition, the macroscopic properties of modified bitumen were also tested. The results show that the samples without cover glass are not influenced by the external perturbation so that the microscopic images are more realistic; there is an interpenetrating and stable network structure formed like ‘lizard skin’ in the sample with 45%(by mass) SBS modifier after swelling for two months. This indicates an excellent macroeconomic performance. ‘Segregation’ phenomena were found in the asphalt samples produced by manufacturers, and a wide variety of ‘coalescence’ was found in microscopic phase. Therefore, the correlation between phase microstructure and macroeconomic performance of SBS modified bitumen is significant. Fluorescence microscopic technique has a great advantage in the detection of modified asphalt performance indicators for a simple preparation and convenient testing method.