Measuring the biodiversity value in monetary could be useful information for policy-makers to estimate welfare losses caused by biodiversity reductions and perform cost-benefit analysis of biodiversity conservation projects. This study applied the approach of contingent valuation to analyze the Mekong Delta urban households' preferences and their willingness to pay for the program of biodiversity conservation in U Minh Thuong National Park, one of the largest peat swamp forests in Vietnam. The study estimated that the mean WTP of urban residents in the Mekong Delta was about VND16,510 ($0.78) per household per month for all respondents and around VND31,520 ($1.49) after excluding the protest zero and scenario rejecting respondents. Aggregately, they agreed to contribute about $10.97 million annually for the project of biodiversity conservation.