Sea-level rise is slow and gradual,but as the time goes on,this progress will become more and more significant,and then this trend intensifies the storm surge,coastal erosion,seawater intrusion and saline tide disaster. Data obtained from the tide-gauge station and satellite observation show that global sea level rose at about 1. 5 to 2. 0 mm/a in the mid-20th century; in the past 30 years, Chinas coastal sea-level rise rate was 2. 6 to 2. 7 mm/a,higher than the global average. Land subsidence of the Bohai Bay at Tianjin was so significant that led to a considerable sea level rise. In the next 50 ~ 100 years land subsidence rate of the Tianjin coastal area may stay in 1. 0 to 2. 0 cm/a range,and the total sea-level rise rate is estimated to be 12. 7 to 22. 7 mm/a according to the current sea level rise rate of 2. 7 mm/a. Therefore,it is expected that the relative sea level in Tianjin will be 48. 3 cm to 86. 3 cm higher in 2050 than in 2012,and up to 111. 8 cm to 199. 8 cm higher in 2100 than those in 2012.