AAKG(L-arginine-alpha-ketoglutarate) is a functional product of amino acid salts with increasing sales in the current international market.The usual form of the product is hybrid rather than crystalline.Herein crystalline AAKG was prepared directly used L-arginine fermentation broth as the raw material and then complexation by adding α-ketoglutarate.The main process steps and control parameters were described as follows.Firstly the L-Arginine fermentation broth was flocculated and filtrated,and then concentrated under reduced pressure to a concentration of 1.0 mol/L.Then it was complexated by adding equimolar α-KG and further concentrated under reduced pressure so that the concentration of AAKG reached 1.5 mol/L.Crude crystals were obtained after the concentrate was cooled at a rate of 2 ℃/h and ultimately crystallized at 10 ℃ for 24h,and then it was recrystallized under the same conditions.The purity of AAKG was 99.2%.The ratio of L-Arg to α-KG was 1∶ 1.02.The total recovery ratio was 62.9%.