Abstract: The electrical analysis was carried out for the vacuum feedthrough of EAST ICRF antenna. The electric field distribution, the electric potential distribution as well as the voltage stand wave ratio (VSWR) varying with the heating frequencies were obtained. Results of analysis demonstrate the design feasibility and rationality of the vacuum feedthough, and provide a theoretical basis for assessing the electric characteristic of the vacuum feedthrough. In addition, the identical methods were applied to perform the electrical characteristic analysis for a new structure of the vacuum feedthrough under the same conditions. Results of analysis demonstrate that the new structure of vacuum feedthrough is better than the original structure of vacuum feedthrough.