As important transitional spaces between buildings and streets, arcades accommodate movement, staying, commerce, and public interaction, and have developed distinctive spatial types in different urban and cultural contexts. Porticoes of Turin and the Qilu of Guangzhou are two representative examples in Italy and South China. Although both are characterized by continuous semi-enclosed interfaces, they differ significantly in formation background, spatial organization, facade expression, and environmental adaptation. These differences reflect not only different processes of urban development, but also the evolution of arcade types under different historical, cultural, and climatic conditions. This study takes Porticoes of Turin and the Qilu of Guangzhou as its objects and compares them from four dimensions: historical evolution, publicness, function, and climatic adaptability.