A novel cross-linked siloxane-based solid polymer network has been synthesized by the hydrosilylation of polymethylhydrosiloxane (PMHS) partly substituted with oligo(ethylene glycol) methyl ether side groups and a alpha,omega-diallyl poly(ethylene glycol) cross-linking reagent. The ionic conductivities of the networks doped with LiTFSI are high at ambient temperature (sigma = 1.33 x 10(-4) S cm(-1) at the optimum LiTFSI concentration EO/Li+ = 20:1). The temperature dependence of the conductivity followed the VTF form, indicating that polymer segmental motion assists the ion transport in the solid networks.