Several examples of proposed flood alarm level comparing to annual flood peaks at critical station are shown in Figures 1-4. At Ban yen station in the North (Figure 1), the moderate floods reach to water level at 474-476m, high floods can reach to 476-478m. If flood alarm level are proposed, floods in 6 years out of 42 collected years (accounting 14%) are over alarm level III, floods in 22 years (52%) over alarm level II and in 38 years(90%) over alarm level I. At Dong Hoi station that located in no-protetction dyke area of Central region (Figure 2), the moderate floods reach to 1.4-1.8m water level, high floods to 1.8-2.0m. The poroposed alarm level shows that in 50 collected years of flood data, there are 16 years (accounting 28%) of over alarm level III, 27 years (accounting 47%) over alarm level II and 49 years (accounting 86%) over alarm level I.