The modified X molecular sieves were prepared by the ion-exchange method and the impregnation method, named as CsX-IE and CsX-IMP respectively. The characterization of CsX-IE and CsX-IMP were carried out by the use of SEM, XRD, FT-IR, BET, TG and CO_2-TPD techniques. The catalytic performance, including the catalytic activity, selectivity and stability, were evaluated in the reaction of the acetone vapor-solid phase condensation using a micro fixed-bed reactor. Characterization results show that CsX-IE and ...