Mesoscale octaantimony decaoxide dihydroxide iodide (Sb8O10(OH)(2)I-2) tubular crystals have been successfully synthesized for the first time through a hydrothermal route from Sb2S3, NaI and NaOH at 200 degreesC. In the process, the Sb2S3 prismatic crystals serve as templates and play an important role in the formation of the Sb8O10(OH)(2)I-2 tubular crystals in alkali aqueous solution. The products are characterized by X-ray powder diffraction and scanning electron microscopy. The sample has tubular prismatic structure. A typical tubule is 6-8 mm in length, 30-50 mum in diameter, and 5 mum in thickness.