The existence of Hydrogen sulfide (H2S) during the petroleum production and its high risks is the main reason to develop a smart, cheap and flexible device for H2S monitoring. This article is focusing on developing electrochemical sensors, which seems to have a promising potential. Polypyrrole (Ppy) and its two composites were prepared; Ppy doped with Cupper oxide (CuO) nanoparticles (Ppy/CuO) and Ppy doped with Tin oxide (SnO2) nanoparticles (Ppy/SnO2) via in-situ polymerization approach. The characterizations of these nanocomposites were confirmed by Fourier Transform Infrared spectroscopy (FTIR), X-ray diffraction (XRD), Dynamic Light Scattering (DLS) and High-Resolution Transition Electron Microscopy (HR-TEM). The testing of these nanocomposites towards the monitoring of H2S gas at different concentrations was carried out in the term of electrical resistance changes. From the data; it was found that the response at 1000 ppm H2S gas concentration was ranked as; Ppy 0.12 %. Ppy/CuO 4.7 %. Ppy/SnO2 53.2 %.