Abstract: Using advanced AVL 657 multi-channel engine analyzer in engine performance test, a synchronous measurement of diesel engine indicator diagram and pressure variation of the high pressure oil pipe was carried out. With analysis of the indicator diagram and computation of heat release rate, the quantitative comparison between the combustion specific properties of diesel and those of emulsified oil as diesel enginefuel was given in the paper. Furthermore, the emulsified oil combustion specific properties and adjustment were discussed.