Castor bean (Ricinus communis L., 2n = 20) is a cross-pollinated diploid species belonging to the family Euphorbiaceae instead of the Leguminosae. It is a native of Africa but may have originated in India. Castor bean plants grow as annual or perennial depending on geographical locations, climate and soil types. Castor bean oil has been used in medicine, printing, dyeing and machine lubrication. Hulled castor bean seeds contain a high content of oil (35-50%) which can be extracted easily by pressure without decorticating, grinding or heating. Furthermore, the chemical composition of castor oil is rich in ricinoleic acid (~90%) which gives the oil some beneficial characteristics. These features make castor bean an ideal oil crop for biodiesel production. Castor bean germplasm is maintained at the USDA-ARS, Plant Genetic Resources Conservation Unit (PGRCU) in Griffin, Georgia. There are 1034 accessions in our collection. However, its genetic diversity has never been evaluated. To explore the potential possibility of using castor bean as a bioenergy crop in the US, 48 accessions have been selected from the collection and planted at Griffin. Seed yield and crude oil content will be recorded and measured, respectively. The fatty acid composition will be determined by Gas Chromatography (GC) with a flame ionization detector (FID). Leaf tissues will be collected for DNA extraction. Genetic diversity of castor bean germplasm in the collection will be evaluated with amplified fragment length polymorphism (AFLP) or existing DNA markers. Accessions with a high seed yield, oil content and proper fatty acid composition will be further investigated for biodiesel production.