A　selective　and　simple　method　for　electrochemical　determination　of　diethylstilbestrol　(DES)　was　developed　based　on　novel　magnetic　molecularly　imprinted　nanoparticles　(MMIPs　NPs)　in　this　paper.　Multilayer　core-shell　type　superparamagnetic　and　water-compatible　MMIPs　(WMMIPs)　NPs　were　prepared　in　aqueous　media　using　3-aminophenylboronic　acid　(APBA)　as　the　water-soluble　functional　monomer.　Moreover,　WMMIPs,　surfactant　hexadecyl　trimethyl　ammonium　bromide　(CTABr)　and　a　composite　of　multi-walled　carbon　nanotubes　coated　with　chitosan　(MWCNTs@CS)　were　stepwise　modified　on　the　surface　of　a　magnetic　glassy　carbon　electrode　(MGCE)　in　order　to　enhance　the　electron　transfer　rate,　increase　electrode　surface　area　for　more　loaded　capture　probes　of　WMMIPs　and　effectively　improve　the　detection　sensitivity　of　the　sensor.　The　prepared　sensor　was　denoted　as　WMMIPs/MWCNTs@CS/CTABr/MGCE.　Scanning　electron　microscopy　(SEM),　ultraviolet-visible　(UV-vis)　spectrophotometry,　Fourier　transform　infrared　spectroscopy　(FT-IR)　and　vibration　sample　magneto.　metry　(VSM)　were　used　to　characterize　the　nanocomposite.　Cyclic　voltammetry　(CV)　and　electrochemical　impedance　spectroscopy　(EIS)　were　used　to　study　the　electrochemical　behaviors　of　the　modified　electrode.　Square　wave　voltammetry　(SWV)　was　employed　for　the　determination　of　DES,　and　the　oxidation　peak　currents　showed　a　well　linear　relationship　with　the　logarithmic　values　of　DES　concentrations　in　the　wide　range　of　1.5　x　10(-9)　to　1.5　x　10(-4)　mol　L-1　with　correlation　coefficient　of　0.9986.　The　detection　limit　was　2.5　x　10(-10)　mol　(S/N　=　3).　The　developed　sensor　exhibited　good　reproducibility,　stability　and　selectivity,　and　was　successfully　applied　to　DES　determination　in　actual　milk　and　lake　water　samples.