Crosslink in solid polymer electrolytes(SPE) affect the Improvement of mechenical properties, the destruction of crystallinity, and the elevation of conductivity. We investigated two types of SPE films which have different crosslinking structures. First, siloxane crosslinked SPE films prepared by sol-gel method have inorganic filler. Second, urethan.e crosslinked SPE films have the simple chemical crosslink. It has been known that inorganic-filled SPE films have excellent thermal, electrical stability and technical properties. In this study, we investigated the thermal and conductive properties of the SPE films having siloxane crosslink or urethane crosslink with the change of temperature and salt contents. We could prepare transparent and amorphous polymer electrolyte films. With the increase of salt content 79 increased. Comparing PEG600 to PEG1000, the T_g of PEG1000 was lower than that of PEG600. The T_g of urethane crosslink was lower than that of siloxane crosslink for PEG600. LiCO₄ was used as salt. In futher study, we will investigate the thermal and conductive properties with the inter-crosslink molecular weight of urethane crosslink.