The oxidative behavior of ascorbic acid (AA) in Ginger Rhizome was studied at a glassy carbon electrode in 0.1 M Na2HPO4-NaH2PO4 buffer as a solvent and supporting electrolyte using cyclic voltammetry (CV), and square-wave voltammetry (SWV). In this study, the ascorbic acid content in Ginger Rhizome was also determined in SWV technique. The effect of ascorbic acid concentration on the response of GCE, pH of phosphate buffer solution and scan rate on the response characteristics of the electrodes were investigated by CV. It is found that the anodic peak current of AA is directly related to concentration and scan rate whereas inversely related to pH. As pH value increases, the anodic peak potential is shifted to less positive and peak current found to decreases. pH2 was chosen for the whole work. A calibration curve was obtained by square wave voltammetry at GCE after wave frequency, step potential, and wave amplitude were optimized. The wave frequency, step potential, and wave amplitude chosen for this work were 25 Hz, 7 mV, and 40 mV, respectively. It is found that, under optimized conditions the anodic peak current is directly related to AA concentration. The amount of AA determined in this work using SWV is 6.769 mg/100 g of ginger. The linear regression equation obtained from the plot was: Ipa (μA) = -7.799 [AA] (μM) – 1.962 with R2 = 0.99171.