The availability of sea weed at the coastal area was used by the community as a commodity that
could be used to earn money. Beside income for the community, sea weed also have ecological benefit that its value could be moneterized. Economic resources valuation is an approach to value the resources, including sea weed. The befenit values of natural sea weed consist of use value that could be estimated by the technique of
effect on production (EOP), otherwise non use value could be estimated by the technique of
contingent valuation method (CVM). The objective of this paper is valuing economic resources of the natural sea weed at the Ujung Kulon coastal using an approach of resource economic valuation.
The result of this study show that the use value of the natural sea weed at the Ujung Kulon coastal is Rp.66.685.861,22 per year or Rp.19.053.103,21 per hectare per year. The non use value can be calculated Rp.263.086.105,98 per year or Rp.75.167.458,85 per hectare per year. Knowing net present value and net cost-benefit ratio could be used extended cost benefit analysis. The result show that using the scenario of 25 year and discount rate 6 percent, NPV of this resources is Rp.86.392.873,63 per hectare per year and Net BCR is 84,99.