X0202 4 2008-04-17 0000073124 NORTHERN TRUST CORP NTRS 0001378549 Potter Stephen N 50 SOUTH LA SALLE STREET CHICAGO IL 60603 0 1 0 0 EVP/President NTGI Common Stock 2008-04-17 4 M 0 4428 45.1563 A 32301 I By Trust Common Stock 2008-04-17 4 F 0 2760 72.435 D 29541 I By Trust Common Stock 2008-04-17 5 G 0 320 0 D 29221 I By Trust Common Stock 2008-04-17 5 G 0 160 0 A 1040 I Spouse as Trustee for Son Common Stock 2008-04-17 5 G 0 160 0 A 1040 I Spouse as Trustee for Daughter Common Stock 15188 D Common Stock 8323 I 401(k) Employee Stock Option (right-to-buy) 41.1563 2008-04-17 4 M 0 4428 0 D 2001-05-13 2009-05-13 Common Stock 4428 19572 D Represents stock units payable automatically on a 1-for-1 basis in shares of the Corporation's common stock. as of 03-31-08 Paul A. Bernacki Attorney-in-Fact for Stephen N. Potter 2008-04-21