This paper is concerned with the preferences of the Finnish households for a controversial nature conservation program – the European Union's Natura 2000 Network. Since the program was mainly based on biological considerations, it met strong public opinions from different interest groups in Finland. Using the choice experimental method, we attempt to estimate the values that the Finnish households would place on different preservation levels. It is found that the mean willingness to accept for a decrease in the nature preservation area is much greater than the mean willingness to pay for an increase by the same amount. Also, the marginal willingness to pay becomes zero after an initial increase in the natural preservation area, which is consistent with our earlier findings in a binary choice valuation study. Policy implications of these results are also discussed in relation to different decision criteria.