Electrochemiluminescence (ECL) is a high- sensitive detection method with broad biological applications. Ruthenium (Ⅱ) tris (bipyridyl) and tripropylamine (TPA) are most commomly used combination of the reactive species in ECL. The redox of with excess TPA at the surface of an electrode produces a highly efficient and stable light emission due to a rapid cycle of the reactions. This rapid, highly sensitive and accurate method has been applied to gene quantification. In this work, an ECL detection system is designed and applied in detection of presenilin-1 (PS-1) gene mutation. The results show that given the same polymerase chain reaction (PCR) cycle number, the ECL intensities from the digested and the undigested wild-type samples are nearly identical, but the difference in ECL intensities between the digested and the undigested mutant samples is distinctive. This detection technology connects PCR with ECL and allows a reliable discrimination between the wild-type and the mutant genes.