Being complex and changeable, WANG Yuyang’s ideas of poetics went through four important transformations. A detailed study of it is required to fully understand the progress of WANG Yuyang’s ideas of poetics and to establish his “theory of poetic charm”. WANG Yuyang’s transformations in his ideas of poetics are the basic problem in our study of his ideas. It is argued that his ideas of poetics at earlier age can’t be viewed as “theory of poetic charm” considering his experience of working as a government official and his active, rich study on poetics. In fact his “theory of poetic charm” went through the transformations from “being abundant, absorbing others’ essences” to “stressing rhyme in Tang Dynasty, and giving priority to literary talent in his poems”, and then to “surpassing three Tang to two Song Dynasties; and absorbing essences from both Tang Dynasty and Song Dynasty”. The “theory of poetic charm” was not established or turned to be mature until the 26th year of Kangxi.