The solvent effect on the synthesis of diethylaluminum azide(DEAA) from diethylaluminum chloride(DECA) and sodium azide(NaN₃) is discussed.In electron-donor tetrahydrofuran(THF) or its mixture with hydracarbon as the reaction medium the product is DEAA·THF complex;in weak electron-donor like hydracarbon the reaction product is DEAA which exists as trime;when nonelecton -donor agent like hexane or cyclohexane is used as the reaction solvent,there is no product formed.With increase of electron-donation of the solvent the product yield also increases,for example, the yield of DEAA sequentially increases in the reaction medium of benzene,tuluene.dimethyl and trimethylbenzene.The other chemical effect of solvents on the reaction of NaN₃ and DECA is also discussed.