The　organic-inorganic　nanohybrids　are　emerging　as　one　of　the　most　attractive　sensing　materials　in　the　area　of　gas　sensors　and　usually　exhibit　some　advanced　properties　because　of　synergetic/complementary　effects　between　organic　molecules　and　inorganic　components.　This　work　demonstrates　a　novel　class　of　organic-inorganic　nanohybrids,　Cu　2+　-doped　SnO　2　nanograin/poly　pyrrole　nanospheres,　for　the　sensitive　room-temperature　H　2　S　gas　sensing.　Doping　Cu　2+　in　SnO　2　nanograins　remarkably　enhances　the　surface　potential　barrier　by　tailoring　surface　defects.　After　polymerizing　pyrrole　surrounded　nanograins　in　aqueous　media　to　form　the　organic-inorganic　nanohybrids,　the　resulting　nanoheterojunctions　further　improve　the　sensitivity.　Additionally,　the　nanohybrids-based　sensor　provides　high　surface　area　and　abounding　reaction　sites　to　accelerate　gas　diffusion　and　adsorption　as　well　as　the　electron　transfer.　Compare　with　pristine　SnO　2　nanograins　alone,　the　sensitivity　of　using　the　nanohybrids　increases　7　times　for　the　detection　of　50-ppm　of　H　2　S.　The　response　and　recovery　rate　can　increase　27　and　22　times　at　room　temperature,　respectively.　Significantly,　this　work　provides　an　attractive　material　for　the　real-time　monitoring　of　H　2　S,　whereas　the　insights　into　organic-inorganic　composite　interactions　within　the　sensing　mechanism　may　pave　the　way　for　designing　functional　materials　with　tailored　properties.　(Chemical　Equation　Presented).　©　2017　American　Chemical　Society.