The effect of proline, glutamine, aspartic acid and their combinations on callus induction and embriogenic callus formation from 3 creeping bentgrass (Agrostis palustris) cv. Regent, Mariner, Cato and 1 colonial bentgrass (Agrostis tenuis) cv. Tiger was estimated in both light and dark condition. The addition of amino acids to the growth medium did not have a significant stimulatory effect on the induction of embryogenic callus, instead, they were inhibitory, particularly at higher concentration (40 mM). But supplement of amino acids at lower concentrations (5 or 10mM) to basal medium was beneficial in inhibiting the formation of hairy outgrowth on the surface of embryogenic callus.