Vietnamis amongst the five countries in the world most likely to be seriously affected by the impact of the global climate change and the sea level rise (SLR). The Vietnamese Mekong Delta (VMD)  is bounded by sea and it highly faces with the risk of the SLR by global climate change. The necessity of investing a concrete sea dyke system in the VMD is still a policy argument. The study is conducted in Tra Vinh province where it has border withSouthEast AsiaSeaand presents a typical situation of the SLR’s impact to the VMD. The purpose of this study is to conduct an economic valuation of the concrete sea dyke system as an adaptation option to the sea level rise’s impact using the risk Cost-Benefit Analysis framework. It uses an ex-ente approach with risk considerations of the storm, flood, and salinity by specifying probability distribution functions in simulation process to incorporate these risk factors into the analysis. The study developed five dyke options associated with three hypotheses of the scales of sea dyke systems: Option 1 for “1 in 20 year storm” scenario, Option 2 and Option 3 for “1 in 50 year storm” scenarios, and Option 4 and Option 5 for “1 in 100 year storm” scenarios. Results showed that the benefits of storm and flood avoided dominated in dyke options. For benefit of salinity avoided, rice and aquaculture productivity losses avoided yearly were 331.25US$/ha and 915US$/ha, respectively. Based on the NPV decision rule, results indicated that dyke options were recommended to take a more consideration as an appropriate adaptation measure for the VMD’s situation. The larger scale dyke systems were, the higher ENPVs were. Among dyke alternatives applicable to the VMD, small-scale dyke options at the initial step and heightened subsequently should be a priority for choice if the SLR’s impacts focused mainly on storm, flood, and salinity factors. The sensitivity analyses showed that the ENPVs of dyke options were very sensitive with changes in discount rate but were not sensitive with increases in salinized areas at all. Findings also show evidences to support the necessity to have a concrete sea dyke system for the Vietnamese Mekong Delta in the context of global climate change.