The electrical characteristics of thunderstorms in three different altitude regions of the Chinese inland plateau have been analyzed in this paper. The results show, according to the polarity of the surface electric (E) field, that the thunderstorms can be divided into two categories in the study regions: one showing the normal tripole electrical charge structure (normal-type), and the other showing the special tripole charge sturcture with a larger-than-usual lower positive charge center (LPCC) at the base of thunderstorm (special-type),where the induced surface E field is controlled by the LPCC when a thunderstorm is overhead. We find that the two types of thunder-storms have different occurrences in different regions, and the percentage of special-type thunderstorms increases with the altitude. On the whole, the flash rate of thunderstorms is quite low, and the mean value is about 1-3 fl/min, while the flash rate of special-type is slightly greater than that of the normal-type thunderstorm. The statistical results of cloud-to-ground flash (CG) numbers indicate that the ratio of+CG flash increases with the altitude, with the value about 14.7 percent through 25.4 percent.