This article adopts the theoretical framework of China Factor in the analysis of the dynamics of Mainland-Hong Kong relations. In recent years, Beijing has increasingly adopted direct and indirect influence mechanisms to shape the affairs of Hong Kong, and paradoxically such attempts have triggered the rise of localism in Hong Kong and resulted in tidal waves of counter-China Factor mobilizations resisting Beijing's interferences. This article concludes that there are growing signs that the issue of center-periphery relations is replacing universal suffrage as the principal political cleavage in Hong Kong. How different political forces in Hong Kong respond and realign with the rise of localism will be a significant weather vane of political development in Hong Kong.