Macau used to be considered as a Portuguese territory until the Constitution of the Portuguese Republic came into force on 25th April 1976.
Under the terms of the article 5th of the Constitution, Macau started to be qualified as a “territory under the Portuguese administration which shall be ruled by a statute adjusted to its new special situation”. The Act 37/81 of 3rd October, which has come into force in Macau on 21st November 1981. Until that date, everyone that was born there was considered Portuguese citizens, no matter whether their parents were Portuguese citizens or not.
After the new Nationality Act came into force, only the children of either Portuguese parent were considered Portuguese.
The territory of Macau was integrated to China on 20th December 1999.
Under the terms of the joint Chinese-Portuguese declaration, from 19th December 1999 on, nobody shall obtain the Portuguese citizenship due to their territorial link to Macau. Notwithstanding, the same declaration states that “according to the Portuguese legislation, the inhabitants of Macau who, on 19th December 1999, were Portuguese citizens may also hold a Portuguese passport, being authorised to continue to use it after this date.”
Differently from Portugal, China does not admit dual citizenship, yet maintain a tolerant position towards their nationals who maintain or obtain the Portuguese citizenship, as long as it is not due to link with the territory.