China's tourism development has made significant progress since the reform and opening-up policy officially launched in 1978. Now it is high time to conduct research on how and why the geographical pattern of China's tourism development has evolved in the previous four decades on national and regional scales. Employing grounded viable data sets (namely the inbound tourism data from 1979 to 2017 and the domestic tourism data from 1991 to 2017) and multiple vibrant data analysis approaches (including the Gini coefficient, the primacy index analysis, the hot spot analysis and the Pearson correlation analysis), this paper can draw three findings. (1) China's tourism can present a distribution pattern of "high in the eastern and southern parts, but low in the western and northern parts." Meanwhile, China's inbound tourism development has long been polarized, Guangdong is the "core" of inbound tourism, Beijing and Shanghai belong to the second tier, while Gansu, Xinjiang, Qinghai, Tibet and Ningxia lag behind. Meanwhile, the domestic tourism development has transferred from polarization to equilibrium distribution. (2) Different stages of China's tourism development exhibit various features and characteristics. Specifically, at the so-called initial modern tourism stage, inbound tourism was subject to extreme polarization, with Guangdong province taking a fatal and strategic role. Whereas, at the domestic tourism cultivating stage, the domestic tourism development in this nation was polarized spatially, though the landscape of the inbound tourism was hardly transformed (Guangdong the first, Beijing the second and Shanghai the third). When it came to the rapid development stage, Beijing was gradually surpassed by Shanghai in the realm of inbound tourism. In contrast, domestic tourism development was reasonably balanced. By the new normal stage, the landscape of the inbound tourism improved, and the first tier provinces began to take an increasing share in terms of domestic tourist reception capacity. Moreover, China's outbound tourism increased steadily at this stage, with Beijing and Shanghai playing leading roles in the citizens' overseas spending. (3) This research has identified multiple factors underlying the inbound and domestic tourism development in China, including policies, management systems, tourism demand, tourism attractions, economic level, consumption level, industrial development, investment status, traffic conditions, accommodation services, intermediary services and degree of openness.