Abstract: Through detailed investigation of farmecosystem diversity in five typical agricultural regions of China, the database of farmecosystem diversity is established. After analysing the characteristics of land use, crop sequence, crop arrangement and distribution of system's units in these regions, the index of each region's farmecosystem diversity is calculated. The results show that the maximum richness of these farmecosystems is quite low and their difference is not significant; the difference among the average richness (Ta) of each region is obvious, and in general, the Ta is higher in hilly areas than in plain areas, but that in plain areas has a trend to decline from south to north.Little difference of enenness (E) and dominance (D) can be found among these farmecosystems, but Eis higher in hilly areas than in plain areas, and D is adverse to E. In accordance with the current situation, some suggestions for constructing diversified farmecosystem structure and for improving farmecosystem diversity are given.

Key words: Agricultural biodiversity, Farmecosystems, Farmecosystem diversity, nitrogen, water and nitrogen productivity, Coffea arabica, drought stress, regression analysis, rewatering, yield