The　peak-aged　state　of　Al-Er-Zr/Hf　alloy　was　annealed　at　450　℃　and　500　℃,　and　the　high　temperature　coarsening　behavior　of　precipitated　phase　in　the　Al-Er-Zr/Hf　alloy　was　discussed.The　results　show　that　after　annealing　at　450　℃,　the　hardness　of　the　Al-Er-Zr/Hf　alloy　decreases　obviously,　while　the　electrical　conductivity　decreases　first　and　then　increases,　and　the　electrical　conductivity　of　the　Al-Er-Zr/Hf　alloy　annealed　at　450　℃　for　100　h　is　higher　than　that　of　the　peak　aged　state.　The　variation　of　the　hardness　and　electrical　conductivity　of　the　alloy　annealed　at　500　℃　are　similar　to　those　of　the　alloy　annealed　at　450　℃,　but　the　electrical　conductivity　of　the　alloy　annealed　at　500　℃　for　100　h　is　lower　than　that　before　annealing　at　500　℃　for　100　h.　The　size　of　precipitated　phase　is　observed　by　TEM.　The　coarsening　process　of　precipitated　phase　in　the　Al-Er-Zr/Hf　alloys　accords　with　LSW　theory,　and　it　is　mainly　controlled　by　the　atomic　diffusion　of　Zr　and　Hf.　The　addition　of　Hf　element　can　reduce　the　the　coarsening　rate　of　the　precipitated　phase　at　high　temperature,　and　the　effect　is　more　obvious　with　more　Hf　content.　©　2018,　Editorial　Office　of　Transactions　of　Materials　and　Heat　Treatment.　All　right　reserved.