By taking the agricultural system in Meixian county of Guangdong province as research object, using the comprehensive utilization of planting and livestock husbandry resources as core constraint condition, constructing agricultural structure optimization model, estimation model of saved purchase emergy, estimation model of increased monetary emergy, the effect of resources comprehensive utilization was assessed based on emergy evaluation approach. The results showed that from 2004 to 2008 the agricultural structure of Meixian county was significantly changed by the comprehensive utilization of planting and livestock husbandry resources. The change of agricultural structure would increase (2.15E+21) sej annual mean monetary emergy. The annual mean emergy exchange ratio increased from 2.57 to 4.42 and the annual mean environment load ratio decreased from 0.62 to 0.17, and the annual mean emergy index for sustainable development increased from 9.27 to 43.52. In conclusion, implementing the comprehensive utilization of resources in Meixian county could decrease environment load ratio and increase emergy exchange ratio, so it could greatly promote agricultural sustainable development.