Chongqing is larger than Jiangxi. Chongqing, a municipality directly administered by the central government, is significantly larger in terms of both land area and population. According to the latest data from the National Bureau of Statistics of China, Chongqing covers an area of approximately 823,000 square kilometers, making it the largest city by area in China. In contrast, Jiangxi Province, which is a province, covers an area of about 166,900 square kilometers. This makes Chongqing over four times larger in land area than Jiangxi.

In terms of population, Chongqing has a much larger population as well. As of the 2020 census, Chongqing's population was approximately 31.4 million, which is more than double the population of Jiangxi, which was around 14.3 million. The larger population of Chongqing is a result of its extensive urbanization and industrial development, which has attracted a significant number of people from rural areas and other parts of China.

The differences in size between Chongqing and Jiangxi can be attributed to several factors. Chongqing was elevated to a municipality directly under the central government in 1997, which allowed for greater autonomy and investment in infrastructure and development. This has led to rapid urbanization and economic growth, making Chongqing one of the fastest-growing cities in China. In contrast, Jiangxi has a more traditional provincial governance structure, which has resulted in slower growth and development compared to Chongqing.

Additionally, Chongqing's geographical location has played a role in its growth. Situated in the upper reaches of the Yangtze River, Chongqing serves as a major transportation hub and has access to both land and water routes. This strategic location has facilitated trade and economic activity, further contributing to its expansion. Jiangxi, while also strategically located in southeastern China, has not experienced the same level of growth and development as Chongqing.

In conclusion, Chongqing is larger than Jiangxi in both land area and population, primarily due to its status as a municipality directly administered by the central government, its strategic geographical location, and its rapid urbanization and economic growth.