A four valence cation conductor Sn4+ Montrnorillonite has been obtained in our lab. The valence state of migrating ion Sn4+ was confirmed with Mossbauer spectroscopy. Its electron eonductivity and AC conductivities were 5.1×10-7 and 1.5×10-4(S/cm) respectively. Some Sn/MnO2 batteries were made using this solid electrolyte with 1.2V OCV and 5mA short current for 13mm×3mm size.