Abstract: The paper analyses the characteristics of animal husbandry subsystem in xiaozhangzhuang village during 1976-1987, and focuses on the characteristic of energy and matter conversions in the subsystem in 1987. It points out that the precent ecosystem in Xiaozhangzhuang village is stable but inefficient. In order to build it as a stable and efficient agroecosystem, we must start with animal husbandry subsystem, that is to sey, we must improve feed conversion rates of animals.