Abstract: The tidal stations in Hong Kong and Macau provide the longest tidal records since 1925 along the coastal region of the South China Sea. However some abnormal errors or omissions during 1953-1956 and 1930-1949 in Hong Kong and 1963-1981 in Macau can be seen. Therefore taking 1959 as a connexion to continue the previous stage of 1925-1958 in Macau with the latter stage of 1959-1996 in Hong Kong, an impartial monthly mean series of sea level starting unify from the sea map base level of Hong Kong during recent 72 years (1925-1996) can be obtained. The sea level curve reveals a fluctuation tendency of sea level rise including abnormal higher and lower sea level, the former is related with the runoff of the Zhujiang River and the latter is in keeping with the strong El Nino year. The rate of sea level rise is calculated as 1.8 mm/a in recent 72 years using by single linear regression, and 2.0 mm/a during 1959-1994 dispeling the high frequency components from Fourier Transform. In addition dividing the series into 11 sets of 1955-1994, 1956-1994...1965-1994, and then calculated the average rate as 1.64?0.25 mm/a. Therefore the rate of 1.8?0.1 mm/a is epitomized from the tidal data in Hong Kong and Macau. The elevation of beach rock, earthquake activity and ground deformation indicate the relative stability of structure in Hong Kong and Macau, so that the rate of 1.8?0.1 mm/a can be deduced as the rise rate of theoretical sea level along the coastal region of South China Sea.