ZIF-67-derived cobalt sulfide wrapped by graphitic carbon nitride (g-C3N4) nanohybrid was synthesized and used for modification of glassy carbon electrode (GCE) to prepare chloramphenicol (CAP) sensor. The catalytic activity of the cobalt sulfide/g-C3N4/GCE toward CAP electroreduction has been investigated using cyclic voltammetry. At the surface of the electrocatalyst, the cathodic peak current for reduction of CAP is higher than that g-C3N4 and ZIF-67-derived cobalt sulfide at lower overpotential.