In this paper, the electrogenerated chemiluminescence (ECL) behavior of 6-(4-methoxyphenyl)-2-methylimidazo[1,2-a]pyrazin-3(7H)-one (MCLA) at an indium-tin-oxide (ITO) electrode in phosphate buffer solution has been investigated when linear sweep voltammetry was applied. The optimum chemical conditions and electrochemical parameters for this ECL system have been investigated in detail. Under the optimum conditions, it was found that the ECL intensity was linear with the concentration of MCLA in the range of 6.0 x 10(-7) to 1.0 x 10(-5) mol/L, and its detection limit for MCLA was 2.0 x 10(-7) mol/L. The possible mechanism for ECL of MCLA at the ITO electrode was also discussion. Furthermore, it was found that some sophora flavescens, such as matrine and oxymatrine, might enhance the ECL intensity of MCLA. Therefore, it is possible to develop a new ECL method for determination of matrine and oxymatrine. (c) 2006 Elsevier Ltd. All rights reserved.