Rhodamine 6G (R6G), a well-known fluorescent dye, has been intercalated into layered potassium titanoniobate (KTiNbO5) through a guest-guest exchange method by using propylammonium titanoniobate (PrNH3 (+)-TiNbO5) as a precursor. The synthesis process, the structure and morphology characterizations for lamellar nanocomposite have been investigated by means of XRD, FTIR, and SEM. The thermostability of R6G(+)-TiNbO5 nanocomposite is discussed on the basis of thermogravimetric and calorimetric techniques. Absorption and fluorescence techniques are applied to study the photoresponse of R6G in hybrid film. The results indicate that R6G(+) cations in thin film are highly fluorescent even at a high dye concentration, which may be due to the formation of J-dimers within the confined galleries.