Isopulegol (IPG) was synthesized from citronellal (CTN) at atmospheric pressure and 40similar to60degreesC in a batch reactor by using mesoporous molecular sieves MCM-41 as well as zeolites HZSM-5 and HP. The catalysts were characterized by the methods of XRD, N-2 adsorption, Al-27 and Si-29 MAS-NMR and TPD of ammonia. Under our reaction conditions, Al-MCM-41 was found to be the best catalyst; it exhibited much higher activity, despite slightly lower IPG selectivity. The catalytic results depend on a variety of factors, viz. the acidity, the pore size and the pore channel of catalysts. The reaction paths were proposed and the kinetic parameters for competitive first order reactions of CTN were estimated.