Vickers　hardness　and　electric　conductivity　measurements　as　well　as　micro-structure　analysis　were　used　to　investigate　the　effects　of　trace　element　Hf　atoms　on　the　precipitation　and　recrystallization　resistance　in　Al-Er-Zr　alloys.　The　results　of　the　present　study　indicated　that　the　behaviors　of　precipitation　process　in　Al-0.04Er-0.08Zr　and　Al-0.04Er-0.08Zr-0.05Hf　(at.　%)　alloys　are　similar.　When　alloys　were　annealed　at　350　°C　for　96h,　the　nano-scale　and　coherent　Al3(Er,　Zr)　and　Al3(Er,　Zr,　Hf)　precipitates　form,　corresponding　to　the　peak　hardness　values　of　56.2　±　0.9　(ternary　alloy),　58.9　±　1.5　HV　(quaternary　alloy),　respectively.　The　higher　peak　hardness　in　Al-0.04Er-0.08Zr-0.05Hf　alloys　mainly　benefit　from　the　decomposition　of　Hf.　It　was　shown　that　the　existence　of　precipitates　could　improve　the　recrystallization　resistance　obviously.　Due　to　the　similar　retarding　force,　recrystallization　temperatures　of　both　alloys　are　almost　the　same,　approximate　450　°C.　©　2017　Trans　Tech　Publications,　Switzerland.