Abstract: The water-soluble p-sulfonated Calix8arene sodium (SC8) was self-assembled onto the surface of reduced graphene oxide (RGO) to form the water-dispersive RGO-SC8 composites. IR, UV-Vis, SEM, TEM, TGA and EC were used for characterizing RGO-SC8 composites. The results showed that, the surface of composite was covered with a large number of SC8, which promoted the dispensability and film-forming properties of RGO. RGO-SC8 exhibited not only the good conductivity and large surface area of RGO but also the high supramolecular recognition and enrichment capability of SC8. And the two components of RGO-SC8 could synergistically improve the electrochemical reactivity and display excellent electrochemical performance for imidacloprid. After RGO-SC8 being modified onto the surface of electrode, electrochemical method was used to determine imidacloprid, giving linear range of 1.0×10-8-6.0×10-5mol·L-1 and detection limit (3S/N) of 9×10-9mol·L-1.