The relationship between aging temperature,time,Al equivalent and mechanical properties of Ti-15-3 (Ti-15V-3Cr-3Sn-3Al) alloy at different heats was investigated.The variety of tensile strength with aging temperature is characterized by a linear relationship at the temperature range of 500～540℃,and the average slope is about(-3MPa/℃).The linear equation between strength and Al equivalent has been obtained,and the optimum Al content is calculated as 3.1%～3.3%.The relationship between strength and ductility was studied by statistical method,and the effect of cold processing on aging characterization was also investigated.The studied aging treatment 520℃/10h/AC reaching the strength grade 1080MPa possessies satisfactory mechanical properties,and this aging treatment was applied to manufacturing a decelerating umbrella beam of aircraft.