What country does macau belong?

Macau is a Special Administrative Region of the People's Republic of China. It is NOT a sovereign state. There was a period until 1999 when Macau was a colony of Portugal. However, after the handover in December 1999, Macau is now Chinese territory, although it still retains a high degree of self-government (the Central Government in Beijing only has jurisdiction over Macau's defence and foreign affairs)
Portugal, until December 20th, 1999.