Synchrotron radiation small-angle x-ray scattering (SAXS) technique was employed to investigate the pores in the insensitive high explosive C6H 6N6O6(TA TB) manufactured by different methods. The microstructure parameters of the por es such as diameter distribution, fractal character, Porod constant, interface parameter and so on were obtained from SAXS results. Analyses of variations of the microstructure parameters were also made. It is shown that there is an obvio us microstructure feature for each TATB sample.