In addition to the geographical mainland, the geopolitical sense of the term includes islands such as Hainan, Chongming, and Zhoushan.

This forced the Kuomintang to relocate the government and institution of the Republic of China to the relative safety of Taiwan, an island which was placed under its control after the surrender of Japan at the end of World War II in 1945.

With the democratisation of Taiwan in the 1990s and the rise of the Taiwanese independence movement, some people began simply using the term "China" instead.

[8] Since the return of Hong Kong and Macau to Chinese sovereignty in 1997 and 1999, respectively, the two territories have retained their legal, political, and economic systems.

Therefore, "mainland China" generally continues to exclude these territories, because of the "one country, two systems" policy adopted by the Chinese government towards the regions.

The two territories are generally considered to belong to the same historical region, Fujian Province, which has been divided since 1949 as a result of the civil war.

Some platforms like Bilibili banned the use of the term "mainland China" in their website and classified the behavior in its convention as an illegal act of splitting the country and undermining the integrity of national sovereignty, which violates law.

However, due to the One Country, Two Systems policy, the two regions maintain a degree of autonomy, hence they are not governed as part of mainland China.

Geographically speaking, Hong Kong and Macau are both connected to mainland China in certain areas (e.g. the north of the New Territories).

[19] References to the PRC and other lost continental territories as the mainland began appearing in Taiwan state documents as early as 1954.

[3][26] In 2012, the Supreme Court of the Republic of China's judgment #900 labeled the Macao Special Administrative Region as the "Mainland's Macau Area".

[33] It refers to the areas under the jurisdiction of the People's Republic of China, excluding the regions of Hong Kong and Macao.

[34] This term is often used in contexts where the special administrative regions of Hong Kong and Macau are mentioned, and in some cases, it is synonymous with "Mainland China".

[38] On 6 December 1984, in a reply by the Supreme People's Court titled "Reply of the Supreme People's Court on the Issue of Whether Civil Cases Involving Hong Kong and Macau Compatriots Holding 'British National Overseas Passports' Issued by the Hong Kong British Authorities and Identity Cards Issued by the Macau Portuguese Authorities in Inland Chinese People’s Courts Should Be Treated as Foreign-Related Cases," it was pointed out that holders of such documents are considered Chinese citizens, not recognizing them as having British or Portuguese nationality; hence their civil cases in Inland Chinese courts should not be treated as foreign-related cases.

[40] This law symmetrically aligns "Inland China" with the Hong Kong and Macau Special Administrative Regions,[41] and in English versions, both are uniformly translated as "Chinese Mainland".

For example, in the "Air Services Agreement between the Government of the Macau Special Administrative Region of the People's Republic of China and the Government of the United Kingdom of Great Britain and Northern Ireland," it is stipulated that "locations in Inland China and Hong Kong shall not be used as intermediate or beyond points.