Grain　refinement　and　precipitation　are　two　effective　ways　to　improve　the　mechanical　properties　of　Mg-RE　alloys.　In　this　work,　a　two-step　forming　process　is　proposed.　This　includes　cold　rolling　and　subsequent　annealing　at　high　temperature　for　a　short　duration.　By　the　two-step　forming　process,　grains　can　be　refined　from　100　mu　m　to　20　mu　m　in　compare　with　similar　to　30　mu　m　by　common　hot　rolling　at　450　degrees　C　for　a　reduction　of　80%.　The　sample　shows　more　distinct　aging　hardening,　as　the　hardness　amplification　of　60　HV　is　twice　that　of　the　hot-rolled　sample.　The　precipitation　is　observed　by　high　angle　annular　dark　field-scanning　transmission　electron　microscopy　(HAADF-STEM).　Dynamic　precipitation　in　the　sample　by　the　two-step　route　is　found　to　be　effectively　suppressed.　Interestingly,　after　subsequent　annealing,　the　density　of　precipitation,　especially　beta＇,　become　much　higher　than　that　in　hot-rolled　samples.