© Copyright Taylor & Francis.The objective of the study is to determine hydrate formation conditions of methane-hydrogen sulfide mixtures. An experimental work is carried out with different H2S concentrations and both brine and distilled water. The Black Sea conditions, which are suitable for methane-hydrogen sulfide hydrate formation, are examined. Effects of H2S concentration and salinity on the hydrate formation conditions are also obtained during the study. It is concluded that an increase in the salinity shifts the methane-hydrogen sulfide hydrate equilibrium condition to lower equilibrium temperatures at a given pressure. With an increase in H2S concentration, the methane hydrogen sulfide hydrate formation conditions reach higher equilibrium temperature values at a given pressure.