Calculations (AM1) demonstrate that Clar's valence bond model predicts the long-range reactivity patternsof hydrogenation of carbon nanotube (CNT) segments. CNT segments behave as other polycyclic aromatichydrocarbonshydrogenation of double bonds is energetically preferred over hydrogenation of aromaticsextets. The frontier molecular orbitals of CNT segments have greatest amplitude at the double bonds,suggesting that Clar's model also predicts kinetic reactivity.