Abstract: Disclosed herein are a novel 2-substituted adenosine derivative having the following formula [I] ##STR1## wherein R represents a hydrogen atom or a hydroxyl group, m is an integer of 2 to 7, n is 0 or an integer of 1 to 3, and R.sup.1, R.sup.2 and R.sup.3, which may be the same or different, each independently represent a hydrogen atom, a hydroxy protective group or a phosphoric acid residue, and salts thereof.The above compounds are excellent in a circulation ameliorating effect such as a vasodepressor activity, and have high selectivity for A.sub.2 receptors, but cause less undesirable side effects such as a suppresssive effect on the heart. They are therefore effective when used in pharmaceutical compositions for circulatory diseases.