SnO2 hollow microspheres (HMSs) have been prepared through a facile hydrothermal route combining with subsequent calcination without any additive templates. The obtained porous SnO2 HMSs process a large specific surface area of 64.2 m(2).g(-1) and exhibit high gas sensing capabilities. Surface loading Pt nanoparticles on SnO2 HMSs improves the sensor response and reduces the operating temperature for achieving high sensitivity, fast response and excellent selectivity to hydrogen at room temperature. The sensor response to 200 ppm H-2 is 21 at 50 degrees C with a response time of 4 s. These remarking sensing properties are attributed to the synergism provided by the unique porous hollow spherical structure of SnO2 HMSs and the catalytic activity of Pt nanoparticles.