Abstract: Silver manoparticles (AgNPs) and ionic liquid of BMIMBF₄ were prepared separately, and mixture of the ionic liquid and 1.5 mol·L^-1 AgNPs solution in the volumic ratio of 4 to 96 was prepared and dropped onto the surface of glassy carbon electrode (GCE) to form the ionic liquid-AgNPs modified GCE BMIMBF₄-AgNPs/GCE after vacoum-drying of the modified GCE at 30 ℃ for 5 min. The specific properties of the modified GCE and chemical behavior of Vitamin C at this electrode were studied thoroughly. It was found that in the SWV determination of Vitamin C by using the modified GCE as working electrode, SCE as reference electrode and Pt electrode as auxiliary electrode, linear relationship between values of peak current and concentration of Vatamin C was obtained in the range of 5 to 100 μmol·L^-1, with its sensitivity of 0.4 μA·μmol^-1. Samples of Vitamin C tablets were analyzed by the proposed method, giving determined values of Vitamin C in consistency with the values reported in literature, the value of RSD (n=5) was less than 2.0%.