Polyurea is a crosslinked thermoset elastometic polymer derived from the chemical reaction between a diisocyanate (NCO-R-NCO) and a diamine (NH2-R- NH2),without the aid of a catalyst or an additional cross linker,which has been widely empolyed in myriad of applications,such as concrete coating,truck-bed liners,marine coatings,railcar linings,water well protection,enhanced construction joints and much more. Though extensive researchs on weather resistance and corrsion resistance of polyurea have been conducted,stress and photo-oxidative of it is rarely reported. In fact,polyurea in the normal work is also subjected to certain tensile stress,and the aging of it is an aging under stress-heat-UV. Therefore it is necessary to study the aging properties of polyurea under stree and photo-oxidative. In this study，polyurea was exposed to different stress and ultraviolet irradiation in an aging oven,and observed at time intervals. The changes in structure were characterized by metallurgiral microscopy,differential scanning calorimetry,attenuated total reflection-Fourier transform infrared spectroscopy,and X-ray diffraction. Moreover,the mechanical properties of polyurea under different aging time were tested.