Abstract: Based on field investigation and experimental data analysis,ecological economic principles were applied to study the structure and function,the characteristics of material and energy flows,and the economic and ecological benefits of a rice crab model.The resutls show that rice crab model had a higher integral benifit than rice model,and its net income,cost benefit ratio,and labor productivity were increased by 382%,67.7% and 295%,respectively.In view of the ecological benefits produced,the total nitrogen,alkaline hydrolyzal nitrogen,total phosphorus,rapidly availlable phosphorus,rapidly available potassium,and organic matter in the soil after 1 year carb breeding were increased by 10.6%, 3.3 %,5.8%,11.7%,3.5% and 10.5%,respectively.Moreover,6375 kg N穐m^-2 of non point source pollution load could be cut down annually.

Key words: Rice crab model, Ecological economic analysis, Ecological agriculture, biocontrol, endophytic bacteria, green fluorescent protein, Bacillus subtilis, colonization threshold