Abstract: Using systematic analysis method the authors studied the statue characteristics and their variation patterns of rural agro-ecolomic type in mid-subtropical region of Fujian province.11 tapes of system structure and their geographical distribution characters are obtained.Suburban type agricuIture is characterized by "planting-processing-trading",mountainous type is characterized by" planting-breedingprocessing",while distant suburban type possesses both of these characters.These three types represent three development stages,i.e.,commodity production stage,transitional agricultural production stage and traditional agricultural production stage, and reflect three cyclic forms,i.e., commodity production cycle,commodity and self-sufficient production dual cycle and self-sufficient cycle.

Key words: nutrition, competitive parameter, Prorocentrum donghaiense, Skeletonema costatum.