The influence of simplex aging and duplex aging on the microstructures and mechanical properties of Ti-10V-2Fe-3Al (Ti1023) alloys were investigated. Results show that for the same aging time, yield strength of duplex aged samples is slightly lower than that of simplex aged samples. However, elongation of duplex aged samples is significantly higher than that of simplex aged ones. Compared with the simplex aged samples, the better combination of strength and ductility occurs in duplex aged ones. SEM fractography of simplex aged samples shows intergranular fracture mode at lower magnification but grain boundary ductile fracture at higher magnification. However, for duplex aged samples, transgranular dimple fracture is dominant. Microstructure observations show that the good combination of strength and ductility of duplex aged samples is attributed to the microstructure of alternately arranged α/β plates, the suppression of continuous grain boundary α film and the decreased strength difference between the β aged matrix and the β grain boundary precipitate zone.