The objective of this paper is to improve a chemiluminescence anal. with emulsion for detecting lipid peroxidationThe different emulsifier, state of oil water emulsion, the solution pH and the numbers of the determination in measuring system were investigated and selected.Repeatability, stability and linear of exptl. results were observedThe results showed that between two states of oil-water dispersal and emulsion, their chemiluminescence values of coefficient of variation RSD is 10.2% and 26.4% under pH 9.2.The lipid peroxidation can not be started by free radical AAPH at low pH, but at high pH it would considerably effect both samples and chemiluminescence.In researched concentration range (AAPH, 2,2'-azo-bis-2-amidinopropane-dihydrochloride 0-125 g·L-1), there was a significant linear correlation between concentration of free radical AAPH and chemiluminescence values (r=0.994 4).It was concluded that the chemiluminescence anal. with lecithin for detecting lipid peroxidation is repeatable and significantly linear at the state of oil-water dispersal of pH 9.2.