Identification and observations of leucine aminopeptidase (LAP) and multiple molecular forms of the enzyme, isozymes, were made with a technique of starch-gel eletrophoresis for various legume pollen. Plants tested other tnan Leguminosae demonstrated either no indication of the presence or at least trace of the enzyme and the isozymes, although all legume pollen tested showed strong LAP patterns. The electrophoretic patterns of LAP failed to be shown if the extracts were heated or otherwise denatured. Extent of zymogrammatic appearance of LAP and the isozymes were characteristic of a species.