In this study, the H2S gas sensing characteristics were evaluated using surface-modified SnO2 microparticles by tip sonication. The surface-modified SnO2 microparticles were synthesized using the following sequential process. First, bare SnO2 microparticles were synthesized via a hydrothermal method. Then, the surfaces of bare SnO2 microparticles were modified with Ti nanoparticles during tip sonication. The sensing characteristics of SnO2 microparticles modified with Ti were systematically investigated in the range of 100–300o C, compared with the bare SnO2 microparticles. In this study, we discuss in detail the improved H2S sensing characteristics of SnO2 microparticles via Ti nanoparticle modification.