This review is structured as follows: We briefly highlight a few fundamental equations related to ionic conductivity and the major factors responsible for controlling ionic conductivity in section II. Then, we categorized the materials based on the framework structures in section III. In each class of materials, we analyze how the framework anions, carrier concentration, and diffusion mechanism affect ionic conduction and how to optimize them. In the section IV, we discuss the general trends and common factors that contribute to fast ion conduction. Then, we demonstrate a systematic approach for achieving an ideal ionic conductor in section V. Finally, there is a conclusion and future directions in section VI.