The relaxation behavior of epoxy with different thermal history was studied by means of stress telaxation DSC，dynamic mechanical measurement and thermo-meeha-nical analysis (TMA) methods．According to stress relaxation measurement，the internal stress of epoxy samples with different thermal history relaxed rapidly，when quenched samples were kept at room temperature．The phenomena of physical aging，i．e．enthalpy or volume relaxation of quenched and annealed samples，observed from DSC testing，are different．For quenched sample an additional physical aging peak shifted to higher temperature and the peak area in-creased with increasing storage time at room temperature．On the contrary for anneal-ed samples，the additional peak shifted to lower temperature and the peak area decreas-ed and disappeared gradually．The Tg of quenched samples，measured by TMA，decreased at first and then in-creased With increasing storage time at room temperature． It shows that there are at least two relaxation processes，internal stress and volume relaxation，which influence the mechanical properties，and the formerone changes faster than the later one．