The water permeability of cementitious composites containing polyvinyl alcohol (PVA) fiber, fly ash (FA) and silica fume (SF) is studied in this paper. The parameters studied include volume fraction of PVA fiber, cement substitution with fly ash and cement substitution with both silica fume and fly ash. The research findings show that with the increase of volume fraction of PVA fiber, the penetration depth of cementitious composites is decreased. The penetration depth increases with the addition of FA and SF. Conclusions were drew that PVA fiber, FA and SF have an obvious influence on the water permeability.