Abstract: Energy is the essential nutrient for maintaining animal life activities,growth,reproduction and performance. Accuracy evaluation of energy requirements and feed energy efficiency for ruminants has important practical significance in ruminant nutrition and production. Therefore,based on comparing the characteristics between different energy evaluation systems, the author summarized and analyzed the research progress of ruminant net energy and feedstuff net energy by different evaluation methods,in order to provide a reference for the application of net energy system in ruminant production.