The phenomenon of chlorophyll retention in soybeans [Glycine max (L.) Merrill] is worthy of investigation for several different reasons: 1) it may have a physiological impact upon yield, 2) it may be useful in helping to explain the process of senescence, and 3) it causes production of green seeds, which may differ from normal yellow seeds in chemical composition, size, germination, nutritional qualities, and/or potential usefulness as vegetable types. Different genetic systems control the retention of chlorophyll, which results in green seed color (1). Ten near-isogenic lines in both 'Clark' and 'Harosoy' backgrounds are currently being studied to characterize and compare the different chlorophyll-retention types with their normal counter-parts.