Nowadays electrochromic materials have been attracting much interest in controllable light-reflective or light-transmissive devices for optical information and storage. These devices have potential use in various applications such automotive industry (rear-view mirrors and visors) and architecture ("smart-windows" for vehicles and buildings) [1]. In this work a new kind of conducting materials produced by solvent-casting technique with commercial gelatin, doped with lithium perchlorate (LiClO4) are reported. Recent attention has been focused on the use of natural polymers due to their biodegrability, low production cost and good physical and chemical properties. The characterization of the electrolytes prepared will be made with data obtained by thermal analysis and studies of ionic conductivity. Electrolyte samples were obtained as transparent, amorphous films and at room temperature the highest conductivity was observed with the gelatin 5% LiClO4 EC + PC composition (2.04x10-9 ohm-1cm-1).