This paper shows experimentally the characteristics of raising up the flashover voltage in supension insulators or bushing according to the theoretical results which was gotten by previous study. It was shown theoretically that, if some conducting metallic barriers are inserted into the flashover discharge path, the flashover voltage is found to be increased considerably. In order to verify this theoretical results, some basic experimental study was done, and the results was found to be more or less satisfactory except some problems which must be considered in future study.