Several ion-exchangeable layered niobates were applied to prepare modified layered photocatalysts. K1-xLaxCa2-xNb3O10 (x = 0, 0.25, 0.50, 0.75), a layered perovskite series, with variable interlayer cation density, were used for the modification of the interlayer space by pillaring of silica and titania. The silica-pillaring process was monitored by NMR and the thermal stability was also examined. Silica-pillar was successfully introduced to all the series of perovskites which showed good photocatalytic activity. The preparation of titania-pillared layered niobates was more difficult. In the case of KCa2Nb3O10 (x = 0), we could not introduce a titania pillar, but in the case of K0.5La0.5Ca1.5Nb3O10 (x = 0.5) carrying less interlayer cation density, titania-pillar was introduced although the thermal stability was very poor. K4Nb6O17, another type of layered niobate, was used for the exfoliation and restacking of the niobate sheets. The structure and photocatalytic activity of the product was examined.