Abstract: The thermo-physical property experiments had been done for the 3D 4-directional braided composites with different braiding parameters in thermal environment. The changing rule and distribution characteristics of the thermo-physical properties for the 3D 4-directional braided composites were obtained. The effects of temperature and braiding angle on the coefficients of thermal expansion (CTE), the coefficients of thermal conduction (CTC), the specific heat(SH) and the thermal diffusivities(TD) were investigated at the same time, by which some important conclusions were drawn. These results can provide an experimental basis for the numerical analysis on the thermo-physical properties and the further studies on the thermo-mechanical coupling behaviors of 3D braided composites.