The thermodynamic cycle of an endothermic hydrocarbon fuel cooled scramjet is a chemical recuperation cycle. An experimental system is built, and a series of comparisons are made at different fuel cooling conditions to investigate the influence of different factors on the chemical recuperation process of endothermic reaction of hydrocarbon fuel and the law governing the chemical recuperation process. Experimental results indicate that the recuperation process of endothermic hydrocarbon fuel consists of chemical and physical recuperation processes. The effectiveness of physical and chemical recuperations can be improved by increasing fuel heating temperature. And the effectiveness of chemical recuperation can also be influenced by the residence time of fuel in the chemical reactor. The low fuel flow rate and high working pressure of fuel can help the improvement of the effectiveness of chemical recuperation, the total effectiveness of recuperation of endothermic hydrocarbon fuel can go up by 10%. (C) 2012 Elsevier Ltd. All rights reserved.