An efficient, environmentally friendly procedure is developed for the condensation of aldehydes/ketones and activatedmethylene compounds by using an aminopropyl-functionalized MCM-41 catalyst in aqueoussolution. Different aldehydes/ketones and activated methylene compounds gave thecorresponding alkenes in 78-97% isolated yields in mild reaction conditions.In comparison with organic solution, the aqueous solution gives higher yields in the same reaction conditions. Furthermore, the aminopropyl-functionalized MCM-41 in aqueous system can be reused for 8 times without significant decrease of activity.