In order to look into the internal structure and electrical properties of insulating Silicone rubbers added reinforcing fillers ; Silica(0-140 phr ), and to examine the behavior of charged particles, and the properties of thermally stimulated current (TSC) are investigated, respectively. From the TSC which are formed by applying the electric field of 2~5 ㎸/mm to specimen at temperature range from -150 to $270^{circ}C$, the results arp as following. In the case of non-filled specimen, four peaks of $delta$, $gamma$ , $eta$ and u are obtained at the temperature of $-120^{circ}C$, $-60^{circ}C$, $20^{circ}C$ and $130^{circ}C$, respectively and the case of filled specimen, three peaks of $delta$, ${alpha}_2$ and ${alpha}_1$ are observed at the temperature of of $-120^{circ}C$, $80^{circ}C$ and $130^{circ}C$, respectively. The origins of these peaks are that, the $delta$ peak seems to the result from the contribution of side chain methyl radical, and the $eta$ peak from the depolarization of space charge polarization owing to added imputity during during manufacturing specimens, and the $eta$ peak from the orientation of $Si-CH_3$dipole, and the ${alpha}_2$ near the temperature of $130^{circ}C$ from carboxyl acid that is formed by the thermal oxidation of high temperature.