The Emerald Ash Borer (EAB), Agrilus planipennis Fairmaire, an invasive beetle native to Asia, was first identified in July 2002 in southern Michigan. Infestation of stressed or otherwise healthy ash trees by EAB larvae can cause the death of trees within two years due to larval feeding on the cambial tissue beneath the bark. Because the Great Lakes region contains billions of ash trees potentially susceptible to attack, EAB is a serious threat both environmentally and economically. Genetic analysis is being conducted to determine the origin of the Great Lakes population(s) of EAB by examining nucleotide sequences of the mitochondrial cytochrome oxidase I subunit (COI) and DNA fingerprints obtained using the amplified fragment length polymorphism (AFLP) technique. To date, we have examined individual beetles representing populations from Michigan and three localities in China. No nucleotide sequence variation has been observed in mitochondrial COI sequences analyzed from beetles in Michigan and the three locations in China. Results will be presented from an initial AFLP analysis using two primer pair combinations, E-AGG/M-CTT and E-ACT/M-CAG. Results from the AFLP analysis should lead to closer differentiation of the various populations. A major hurdle in our work is that EAB samples from the beetle's natural range in Asia are rare, especially in Japan and Korea. More complete sampling will be needed to estimate the geographic origin(s) of the Great Lakes EAB population(s).