As an ecologically vulnerable region where atmosphere, hydrosphere, geosphere and biosphere interact, the Yellow River Delta plays an important role both in economy and environment in China. The emergy theory is based on the theory and methods of the System Ecology. Forming 1J higher quality energy will need a large amount of lower quality energy. In other words, different forms of energy have different attributions. By dealing with the energy-value-process of ecosystem, the theory provides us with a new approach to the economic ecology. Based on emergy analysis, this article systematically analyzes energy, resource flowage and condition of eco-economy system in the Yellow River Delta. On the basis of the evaluation indicator system, resources-environment-economy system in the Yellow River Delta is assessed comprehensively. The results indicate that the total emergy consumption of the study region is about 1.76×1022sej,or about US$ 8.42×109. The waste emerge evacuated from the study region reaches about 5.74×1021sej,or about US$ 2.74×109, which indicates that environment in the Yellow River Delta degenerates rapidly because of the industrialization and economic increasing. Finally, based on the calculation of the emergy sustainable indices (ESI), we find that economy increasing of the study region depends on resources consumption. Although the value of resource reserves in the Yellow River Delta reaches US$ 4.45×1012 (about 529 times larger than GDP), it is difficult to use it adequately because of technical limits. So enhancing the resources utilization efficiency and reducing waste are the primary tasks in the future in order to realize sustainable development in the Yellow River Delta.