A palladium(II)-aminosilane complex supported on MCM-41 (Pd-AEAPSi/MCM (1)) was prepared by the complexation of palladium(II) acetate to 3-(2-aminoethyl)aminopropyl (AEAPSi) groups grafted on MCM-41. FT-IR and C-13 CP MAS NMR studies indicated that AEAPSi chelated to palladium(II) to form the Pd(II)-AEAPSi complex. Regioselective hydrogenation of dienes was carried out by the obtained 1 as a catalyst. Pd-AEAPSi/MCM exhibited remarkably high reaction rates for the dienes with a hydroxyl group such as geraniol and linalool, while for limonene without OH group the reaction rate, was notably low. The MCM-supported catalyst also showed noticeably high regioselectivity in the hydrogenation of dienes with OH group. These results indicate that the hydrophilic interaction between the MCM-41 surface and the substrates plays an important role in the rate-determining step. (C) 2002 Elsevier Science B.V. All rights reserved.