This article uses Athens in the early Roman Empire, the province of Achaia, and the political culture behind it as a research environment. Then focuses on two public spaces in Athens: Classic Agora and Roman Forum, which are used as cases to research the relationships between these public spaces. Based on the dynamic evolution of public buildings, monuments, and new public spaces in Athens during that period, this article explores the reasons for this adaptation and transformation of the Forum to Agora in the Roman period. Research suggests that the construction and existence of public buildings and monuments in Athens during the Roman period may have played a major role in promoting this transition from Agora to Forum.