La2O3/AAO nanoarrays catalysts were controllable prepared with anodic aluminum oxide (AAO) template by sol-gel method, and catalytic activity of the catalyst was tested using aldol condensation of acetone to diacetone alcohol as a probe reaction. The catalysts were characterized by XRD, SEM, TEM, BET and CO2-TPD. The results showed that La2O3 were highly and homogeneously dispersed on the AAO surface. When the calcination temperature was 900 ℃, calcination time was 1 hour and the reaction time was 3 h, La2O3/AAO-900 catalyst showed the highest catalytic activity which the conversion of acetone was 4.01 % and the selectivity to diacetone alcohol was 96.32 %. The activity and selectivity of La2O3/AAO-900 catalyst remain basically unchanged after five runs. The higher catalytic performance of La2O3/AAO-900 catalyst is attributed to its larger specific surface area, weak basic sits and a large basic amounts.