Nanostructures tin (IV) oxides have been synthesized by chemical vapor deposition (CVD) and sol-gel methods and their composites incorporated with multi-wall carbon nanotubes have also been obtained. The characterization of oxidized carbon nanotubes (CNTs) by Raman spectroscopy revealed more defects in CNTs with larger diameters. The tin (IV) oxide nanostructures have been investigated by X-ray diffraction methods, electron spectroscopy and Ramani spectroscopy and results have been showed that SnO2, synthesized by CVD method, characterized by more crystalline structure comparatively to the tin (IV) oxide sample, obtained by sol-gel technology. Sensitivity measurements of SnO2, CNTs and SnO2/CNTs samples towards hydrogen have been carried out. It was found that synthesis method affects not only on physical properties of tin (IV) oxide, but also on the sensing properties. In the case of CNTs samples sensitivity significantly depends on the diameter of carbon nanotubes and oxidation conditions imperceptibly influence on CNTs' sensing respond. The addition of carbon nanotubes has an ambiguous effect on the sensitivity and the sensing respond strongly depends on CNTs content in the composites.