The 1990 Chinese census, officially the Fourth National Population Census of the People's Republic of China, was conducted by the National Bureau of Statistics of the People's Republic of China.[1] Based on the fourth census of July 1990, mainland China's population was estimated to be 1.133 billion.[2][3] According to the 1990 census, there were 56 ethnic nationalities with a total population of 1,133 billion. Among them, the Han Chinese had a population of 1.042 billion (94% of overall population).[4]