A new solid proton conductor Na7[CoCrW11O39 (H2O)]·15H2O has been synthesized for the first time. The percentage composition of the product were determined by inductively coupled plasma (ICP) and X-ray photoelectron spectroscopy (XPS). The product was characterized by infrared spectroscopy (IR) and X-ray diffraction (XRD), which indicate it possesses the Keggin structure. The TG-DTA curve shows the sequence of water loss in the compound, the amount of the loss, as well as the thermostability. Conductivity of the compound was investigated by four-electrode method at room temperature and different measuring temperatures, the results reveal that its proton conductivity is 9.42×10−7S·cm-1 at 25°C.