Tungstate-based inorganic−organic hybrid nanobelts/nanotubes were synthesized in a system of H2W2O7·xH2O/n-octylamine/heptane (n-octylamine:H2W2O7·xH2O molar ratio: 30), and the effects of the volume ratios of heptane to n-octylamine and the amounts of interlayer water in H2W2O7·xH2O on the formation behavior of the hybrids were investigated. The belt/tubelike hybrids obtained were 10–20 +m in length and 200–500 nm in apparent diameter. Large volume ratios of heptane to n-octylamine not only enhanced the degree of the long-range order of the lamellar structures in the hybrids, but they also improved the morphologic uniformity of the hybrids. The existence of interlayer water in H2W2O7·xH2O was indispensable to the formation of tungstate-based inorganic−organic hybrid nanobelts/nanotubes. The amounts of interlayer water in H2W2O7·xH2O varied over a wide range (x, from 0.85 to 4.1), had a neglectable effect on the morphology of the tungstate-based nanophase hybrids, but exerted a remarkable influence on the rate of the reaction of H2W2O7·xH2O with n-octylamine in the heptane solvent. The larger the amount of interlayer water, the more rapid the reaction rate.