In this work, we first report a new application of coal as a novel modified electrode material in electrochemical sensing, achieving excellent electrochemical performance similar to graphene and making the utilization of coal become more multipurpose and more meaningful. Raw coal was first ball-milled, then centrifugated, and finally annealed, thus obtaining annealed coal that possesses lots of edge-plane-like defective sites, resulting in good electron-transfer efficiency and excellent electrocatalytic activity, which makes it promising when used as signal amplifier material and as a modified matrix in electrochemical sensing. And we also described an investigation into the electrochemical and spectroscopic properties of annealed coal samples and their application for the detection of electroactive redox molecules (rutin). Compared with other published carbon materials modified sensors, the annealed coal/chitosan/GCE sensor exhibited excellent electrocatalytic activity for the determination of rutin with good sensitivity, providing a wide linear detection range from 0.001 to 10 μmol dm-3 and a low detection limit of 0.2 nmol dm-3 (S/N = 3). Moreover, when the annealed coal/GCE sensor was applied for the determination of ascorbic acid, dopamine, uric acid, guanine, and adenine commonly contained in blood samples and urine samples, it also exhibited excellent detection performance with strong electrocatalytic activity. This research has opened up the application of coal in electroanalytical chemistry and held great promise for the sensing and biosensing application, which can be promising used as an alternative material of graphene.