Al-Ti-B-Er　refiner　was　successfully　prepared　by　CR　(contact　reaction　process),　a　process　based　on　SHS　(self　propagating　high-temperature　synthesis).　The　microstructure　of　the　alloy　was　studied　by　optical　microscopy,　X-ray　diffraction　(XRD),　scanning　electron　microscopy　(SEM)　equipped　with　energy-dispersive　spectrometry.　The　results　showed　that　Al-Ti-B-Er　alloy　was　composed　of　alpha-Al,　block-like　TiAl3　and　flocked　TiB2.　Compared　with　Al-Ti-B　refiner,　formation　of　TiAlEr　compounds,　Er　modified　the　morphology　of　TiAl3　phase,　and　dispersed　the　TiB2　and　TiAl3.　An　excellent　grain　refining　performance　was　obtained　when　adding　1　wt.%　Al-Ti-B-Er　in　Al-10Zn-1.9Mg-1.6Cu-0.12Zr　alloy,　the　average　grain　size　was　about　40　mu　m.　The　refinement　mechanism　of　Al-Ti-B-Er　was　also　discussed.　Er　changed　the　morphology　of　TiAl3,　TiB2　phase,　the　refiner　would　be　more　efficient.　The　decomposition　of　TiAlEr　compounds　which　released　Er　refrained　the　growth　of　TiAl3　and　made　TiB2　difficult　to　aggregate　or　deposit,　therefore　resulted　in　more　particles　being　efficient　nucleation　substrate.