Alkylation of benzene with ethanol for synthesis of ethylbenzene was performed over parent zeolites and zeolites modified with La2O3, such as HMCM-22, HBeta and nano HZSM-5 in a fixed-bed reactor at CO2 flow. The properties of zeolites and catalysts were characterized by XRD, BET and NH3-TPD. The results indicated that zeolite catalysts modified with La2O3 showed high conversion of benzene and high selectivity of ethylbenzene, i.e., 25 % conversion of benzene and 92.72% selectivity of ehtylbenzene over 3%La2O3-HZSM-5(Si/Al=200) respectively. The high selectivity of ethylbenzene is attributed to the proper acid property of modified HZSM-5, and it can be concluded that acid properties is the main factor to affect on this Alkylation. In addition, the deactivation obviously restricted over 5%La2O3-HMCM-22 and 3%La2O3-HZSM-5(Si/Al=200) on time on-stream of reaction, due to enhancement of anti-coking capability and hydrothermal stability after modification.