A　triple-microstructure　with　the　precipitation　of　silicide　along　the　alpha/beta　phase　boundaries　and　a　2　phase　in　the　Ti-5.8A1-3Sn-5Zr-0.5Mo-1.0Nb-1.0Ta-0.4Si-0.2Er　alloy　was　prepared　for　improving　thermal　stability　and　creep　resistance.　The　alloys　were　forged　at　1050　degrees　C　and　1000　degrees　C　followed　by　solution　treatment　at　1000　degrees　C　for　1　h　and　subsequent　ageing　at　700　degrees　C　for　5　h.　The　effects　of　a　morphology　and　precipitation　characteristics　on　the　thermal　stability　and　creep　performance　of　high-temperature　titanium　alloy　were　investigated.　A　triple-microstructure　with　the　participation　of　silicide　along　the　alpha/beta　phase　boundary　and　a　2　phase　was　a　promising　structure　with　improved　thermal　stability　and　creep　resistance.　The　plasticity　loss　rate　was　25.0%　after　thermal　exposure　at　650　degrees　C　for　100　h　due　to　the　participation　and　coarsening　of　a　2　and　silicide.　Meanwhile,　the　plastic　creep　strain　was　0.111%　during　the　creep　deformation　at　650　degrees　C　for　100　h　with　an　applied　stress　of　100　MPa,　which　was　attributed　to　the　inhibition　of　silicide　and　alpha(2)　phase　for　boundary　migration　and　dislocation　slipping.　Furthermore,　the　mutual　precipitation　of　coarsening　silicide　and　a　alpha(2)　phase　inside　a　matrix　was　alpha　significant　reason　for　the　dramatic　decrease　in　the　thermal　ability,　which　also　worsened　the　inhibition　for　dislocation　climbing　of　silicon　element　during　the　creep　deformation.