Abstract: Solution treatment at different temperatures ranging from 700℃ to 820 ℃ and aging treatment at 515 ℃ were carried out for Ti-1023 titanium alloy. Quantitative analysis was performed on the size and distribution of phases in the microstructure of heat-treated Ti-1023 alloy, revealing the correlation between solution temperature and microstructure,room-temperature tensile properties. The results show that the size and number of primary α phase in Ti-1023 alloy solution-treated at 700℃ is the same as that of the original sample. With the increase of the solution temperature, the number of primary α phase gradually reduces, small-sized primary α phases dissolve and disappear rapidly, while large-sized primaryα phases dissolve at a slower rate.The influence of size and number of α phase on tensile properties is significant, the tensile strength and yield strength decrease with the reduction of α phase, and the yield strength decreases more significantly. The precipitated α' phases during aging can markedly improve the tensile strength and yield strength of Ti-1023 titanium alloy,whereas, the ductility tends to decline with the increase of α' phase content.