Abstract: With the aggregates of land resources as the object of study and based on the Fuzzy regional division of various types of productive forces, the potential land productivity,foodstructure and population Supporting capacity on Hainan Island are computed,with considering the input and transformation of material and energy of land resources.The resultsshow that the average biological production potential of 5 kinds of land resources is 5.25×10⁴ kg·hm^-2, equivalent to 2.36×10⁴ kg·hm^-2 standard grain. The population supporting capacity based on low, medium and high food structure programmes are 1.9573×10⁷, 1.5481×10⁷ and 1.2957×10⁷ population, or 52.5, 42.0 and 34.5 population perhectare,respectively. At present. the proportion of the population to that be able to provide for support is 34.2,43.3 and 51.8%,and by the year 2010,the proportion will be 44.5, 57.5 and 68.7%, respectively.

Key words: Land resources, Fuzzy regional division, Biological production potential, Food structure optimization, Population supporting capacity, secondary substance, nutritional substance, Frankliniella occidentalis, protective enzyme, detoxification enzyme