High and low content of montmorillonite incorporated polymethylmethacrylate matrix in the presence of lithiumtriflate salt was investigated and studied. All samples were synthesized using the solution cast technique method. Different techniques (X-ray diffraction, FT-IR, DSC, TG, and SEM) were used for structure characterization. X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) analyses confirmed the complete dissolution of lithiumtriflate salt and intercalation of montmorillonite within the polymethylmethacrylate matrix. The different contents of montmorillonite showed different behaviors in both of structure and properties. The sample containing the low content of 5 wt% montmorillonite showed the highest AC- conductivity value (σAc = 2.09 × 10−6 Ω−1.cm−1, at room temperature) with a big difference to the other ones. The same sample also showed a good thermal stability (Td = 378 °C). Electrochemical stability of the same sample was also studied. All results were collected and discussed.