How big was the largest Japanese-occupied area of ??China during World War II?

During the Anti-Japanese War, the effective calculation of the number of occupied cities above the provincial level in China was: 1,001 (not the 1,500 cities wildly claimed). Among them: 11 provincial cities, 5 municipalities, 970 counties, 8 prefectures, and 7 league banners. The total occupied area was 3,561,080 square kilometers, accounting for 37.2% of the country's total area (not most of China as claimed, but most of the economic and population center areas were indeed occupied).

A total of 9 provinces in China have fallen. They are: Taiwan Province, Liaoning Province, Jilin Province, Heilongjiang Province, Jehol Province, Chahar Province, Hebei Province, Shandong Province and Jiangsu Province.

There are 13 partially occupied provinces. In descending order of occupied area, they are: Henan Province, Shanxi Province, Anzheng Province, Zhejiang Province, Suiyuan Province, Guangdong Province, Hubei Province, Guangxi Province, Hunan Province, Jiangxi Province, Fujian Province, Guizhou Province and Yunnan Province.

Five of the six municipalities directly under the Central Government in China fell successively: Peking, Tianjin, Shanghai, Nanjing, and Qingdao