In order to elucidate how zeolne structure and alkylating agent play roles in the shape-selective catalysis, the alkylation, i.e., isopropylation, secbutylation, and tert-butylation, of naphthalene (NP) was examined over three-dimensional twelve-membered (12-MR) zeolites, Y (FAU), Beta (BEA), and CIT-1 (CON), andcompared to that of H-mordenite (MOR). The P,P-selectivities (for beta,beta-dialkylnapthalene (P,P-DAN)) and the 2,6-selctivities (for 2,6-dialkyl naphthalene (2,6-DAN)) among DAN isomers varied with the types of zeolites and alkylating agents. EAU, BEA, and CON gave only low selectivities for 2,6-diisopropylnaphthalene (2,6-DIPN) in the isopropylation, and predominant isomers were bulky and thermodynamically unstable alpha,beta-DIPN (1,3-, 1,6-, and 1,7-DIPN) and alpha,alpha-DIPN (1,4-and 1,5-DIPN) at lower temperatures, and the formation of the less bulky and thermodynamically stable P,P-DIPN (2,6- and 2,7-DIPN) increased with increasing the temperature: they have quite different features from the shape-selective catalysis over MOR. These results suggest that FAU, BEA, and CON are not shape-selective in the isopropylation, and that the isopropylation is principally controlled kinetically at lower temperatures, and thermodynamically at higher temperatures. The beta,beta-selectivities over EAU, BEA, and CON increased with increasing the bulkiness of alkylating agents, and were almost 100% in the tertbutylation. On the other hand, the 2,6-selecti vi ties over these zeolites were much lower than those over MOR at a typically moderate temperature, 250 degrees C. These results mean that EAU, BEA, and CON have the shape-selective nature to give the less bulky isomers, P,P-DAN, in the secbutylation and tert-butylation by using bulkier alkylating agents, particularly 2-methyl-2-propene: they can differentiate P,P-DAN from their isomers at the transition states by the steric restriction of zeolite channels. However, the channels of these zeolites are too large for differentiating 2,6- and 2,7-DAN even with 2- in ethyl -2-propene. (C) 2008 Elsevier B.V. All rights reserved.