SnO2 nanomaterials with different morphologies, such as nanofilms, nanorods, and nanowires, were fabricated by sputtering and thermal evaporation methods. Their hydrogen sensing properties were then investigated. The structural characterizations showed that the SnO2 in these nanomaterials was tetragonal. The surface-to-volume ratio of the nanofilms, nanorods, and nanowires increased, leading to an increase in the effective surface area. Gas sensors based on these SnO2 nanomaterials showed a reversible response to hydrogen at various concentrations. The response order of the nanofilms, nanorods and nanowires was enhanced while the peak operating temperature was decreased from 250 to 150 C, and the response or recovery time became shorter. The results indicated that the sensor response effectively increased as the effective surface area of the SnO2 nanomaterials increased, demonstrating that gas-sensing properties could be significantly improved by changing the nanomaterial morphology.