Underground church

The term underground church (Chinese: 地下教会; pinyin: dìxià jiàohuì) is used to refer to Chinese Catholic churches in the People's Republic of China which have chosen not to associate with the state-sanctioned Catholic Patriotic Association; they are also called loyal church (Chinese: 忠贞教会; pinyin: zhōngzhēn jiàohuì). "Underground" does not mean the underground church is secret (in contemporary China, the community mostly operates openly) but refers to its lack of official approval and lack of official support. Underground churches came into existence in the 1950s, after the Chinese Communist Party's proclamation of the People's Republic of China, due to the severing of ties between Chinese Catholics and the Holy See.

Beginning in the 1990s, the Vatican encouraged unity between the "Underground" and the "Patriotic" church. In May 2007, Pope Benedict XVI wrote an open letter to all Chinese Catholics, stating that there is one Catholic Church in China and that despite the two communities (i.e. the "Patriotic" Church and the "Underground" Church) there is no schism between them. Benedict XVI stated that sacraments performed by the priests not in unity with the Vatican were valid but also illicit. He stated that the Catholic Church accepts the legitimacy of the civil authorities in secular matters and that the Pope has authority in ecclesial matters, and therefore the involvement of the Chinese Catholic Patriotic Association in the appointment of bishops (and its bishops conference) violated Catholic doctrine. The letter also removed the permission granted by the Vatican in 1978 to the Underground church to appoint bishops without Vatican approval.

There continue to be tensions between underground churches and "open churches" which have joined the state-sanctioned Catholic Patriotic Association (Chinese: 中国天主教爱国会; pinyin: Zhōngguó Tiānzhǔjiào Àiguó Huì).