Heavy selection on US soybean cultivars (Glycine max) has narrowed genetic diversity and limited the efficiency of trait development within current germplasm. One possible solution to increase genetic variability is to introgress traits from its wild progenitor, Glycine soja. An area of concern in the Midwest is soybean aphid (Aphis Glycines) infestation that costs growers millions of dollars in terms of yield loss and pesticide applications. Our project goal is to characterize soybean aphid resistance in G. soja and develop G. max × G. soja recombinant inbred lines by single-seed descent that could be used in a public or commercial breeding program for trait development. Here we present our findings of a greenhouse non-choice test on parental lines of G. soja inoculated with aphid biotype 2 (OH). PI 549046 was selected from this test as putatively resistant and we then created an F2 mapping population (PI 549046 × Williams 82), inoculated it with aphid biotype 2 and tested it in the field. The resulting phenotypic scores are reported. Future work is aimed at mapping the genetic resistance in PI 549046 across multiple environments.