TC21　titanium　alloy　was　solution-treated　in　temperature　range　of　880°C-950°C.　The　influence　of　solution　temperature　on　microstructure　of　the　alloy　was　studied　by　using　OM,　TEM　and　EBSD　technique,　with　focus　on　the　effect　of　solution　temperature　on　the　formation　of　block　α　phase.　It　is　found　that　block　α　phase　only　exists　at　lower　solution　temperatures,　while　no　block　α　phase　is　observed　in　TC21　titanium　alloy　at　higher　solution　temperatures.　EBSD　orientation　analysis　shows　that　the　orientation　of　block　α　phase　and　β　phase　has　the　Burgers　relationship.　Microhardness　of　the　alloy　shows　the　minimum　value　at　solution　temperature　of　900°C,　then　increasing　with　increase　of　solution　temperature　above　900°C.