The tensile tests of 3-dimension and 5-direction braided/epoxy resin composites were carried out at 150°C and 180°C with 15 minutes, 10 hours and 30 hours heating period of time, respectively. The reasons for the variations of tensile property of these composites with different heating period of time at 150°C and 180°C were analyzed. At 150°C and 180 °C，with heating period of time increasing the tensile strength of samples keeps the same level. the average tensile strength of samples at 180 °C is decreased only 5.0% compared with that at 150°C. The variation coefficient (CV) of tensile strengths at 180°C is also close to that at 150°C. These show that the tensile strength of 3-dimension and 5-direction braided/resin composites has no great change under 180 °C. However the resin in samples tested at 180°C is damaged more seriously than that at 150°C. The reason of damaged resin no great effect on tensile strength is that at high temperature, 3-dimension and 5-direction braided reinforcement still keeps an integrated structure, which can recuperate the loss of tensile strength made by resin damage. So the structure of reinforcement plays an important role at the tensile property of 3-dimension and 5-direction braided/resin composites at high temperature. The results derived from this paper will provide a useful reference for the application of 3-dimension and 5-direction braided/epoxy resin composites at high temperature and over a relatively long period of time.