Narrow leaflet soybean varieties tend to have more seeds per pod than broad leaflet varieties. A gene regulating leaflet shape, ln, was cloned recently. Molecular studies indicated that the transition of the leaflet shape is associated with an amino acid substitution in the EAR motif encoded by a gene (designated GmJAG1) homologous to Arabidopsis JAGGED (JAG) that regulates lateral organ development and the mutation exerts a pleiotropic effect on the fruit patterning. However, the GmJAG1 homeolog, GmJAG2, showed no sequence difference between narrow and broad leaflet varieties and appears to be sub- or neo-functionalized. However, diversity of leaflet shape in soybean germplasm is so high that we are tempted to hypothesize that multiple genes control leaflet shape in soybean. Here we will present our current research results from genetic and sequence analysis of a set of soybean germplasm with an objective to find out genes other than ln involved in leaflet shaping in soybean.