There are many magnificent monuments, from big cities to even small towns, in ancient Rome. These public buildings built by emperors and local elites are today’s famous Roman tourist sites. This essay will study the famous Roman public buildings—the religious building, amphitheater, and baths and understand how they influenced the rule of Rome and why emperors and local elites built so many public buildings. This study will combine archeological and written sources to analyze. Emperors and local elites used religion and many kinds of entertainment as a kind of soft power to maintain and consolidate their rule, which encouraged the rulers to build more baths, amphitheaters, and temples. Religious buildings aimed to unify people in the conquered area into Roman and make various regions in harmony under the same ruler. Both amphitheaters and baths provided people with various entertainments, which became an essential session in Roman social life and made it easy for rulers to consolidate their region. Amphitheaters could also function as places for political purposes. Public architecture could be regarded as a means of soft power, which brought Roman prosperity and the fate of collapse.