Soybean (Glycine max (L.) Merr., var. Chippewa 64) plants were grown in culture solutions containing 14C ring-labeled 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine (atrazine). Culture solution temperatures were varied but ambient temperature about the shoots was constant. The amount of atrazine absorbed increased with increases in herbicide concentration, absorption time, and root temperature. Root temperature had more influence on atrazine accumulation in stems and leaves than in roots. Transpiration rates of atrazine-treated plants were reduced at least 50%.