In the present work,functionalized ionic liquid of 1-vinyl-3-ethylimidazolium bromide (ViEtIm+Br-) was firstly synthesized by reaction of 1-vinylimidazole and 1-bromoethane.Poly(1-vinyl-3-ethylimidazolium bromide) polymeric ionic liquid (Poly(ViEtIm+Br-)) was obtained through polymerization reaction of (ViEtIm+Br-) by using azobis (2-methylpropionitrile) as initiator.Then,the composite of polymeric ionic liquid modified multi walled carbon nanotube (Poly(ViEtIm+Br-)/MWCNTs) was prepared under mild conditions through a non conjugated method by taking advantage of strong π-π interaction between MWCNTs and imidazole group,which was designed as an efficient electrode modifider for the simultaneous determination of UA,DA and UA.The experimental results showed that the Poly(ViEtIm+Br-)/MWCNTs/GCE displayed a linear response for DA,AA and UA in the range of 2-180 μmol/L,50-5 000 μmol/L and 4-50 μmol/L,respectively,and the detection limits were 0.4，22.2,0.9 μmol/L,respectively.The Poly(ViEtIm+Br-)/MWCNTs/GCE was successfully used for the detection AA in vitamin C injection and DA in dopamine hydrochloride injection with recoveries of 98.8%-101%.