A review of the investigations on the sea 1eve1 changes in South-china sea is presented. The full set of year1y sea 1eve1 data at 25 tide gauges a1ong Vietnam coast is used for extreme analysis and trend analysis. Based on the level data collection up to year 2007 the empirical extreme analysis yields new estimates of the design values of sea level with different rare frequencies. The results of extreme analysis are compared with the theoretical extreme heights of tide obtained by predicting hourly tide heights in a 20-year period. .
