This paper describes sensitive ascorbic acid (AA) determination on montmorillonite clay and silk protein sericin nanocomposite (MMT-Ser NC) modified pencil graphite electrode (PGE) for the first time. Nanocomposite structures were synthesized by desolvation technique and cross-linked with glutaraldehyde (GA). The synthesized MMT-Ser NC was evaluated by various methods. As a result of the characterization studies, it was determined that the sericin was successfully converged with the montmorillonite structure, and that the MMT-Ser NCs were homogeneous and uniform, with the size of 150 nm and zeta potentials of approximately-27.6 mV. MMT-Ser NC modified electrodes were evaluated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). Under the optimized conditions, working linear range for the modified sensor was found as 10-1000 µM with square wave voltammetry and the limit of detection (LOD) was found as 8 µM. The relative standard deviation for reproducibility was calculated as% 4.82 (n= 6). Real sample analysis was performed with drug samples and the recovery values ranged from 94.64% to 111.2%.