Hydrate formation has been studied for a synthetic natural gas mixture in pure water and in aqueous solutions containing electrolyte(s), methanol, and a combination of (electrolyte + methanol). Special attention has been given to (electrolyte + methanol) systems, as such data are extremely scarce in the open literature yet are of industrial significance. Sixteen experiments (a total of 107 data points) have been performed in the temperature range of (260.8-281.9)K and pressure range of (0.54-11.18) MPa using the isothermal pressure search method. The generalized hydrate model proposed by Zuo et al. (1996) has been applied successfully to predict the measured data for aqueous systems containing pure water, electrolyte(s), or methanol. A simple exponential expression is proposed to correlate the measured data for aqueous systems containing both electrolyte and methanol. It was found that the addition of methanol would affect the sequence of inhibiting strength of methanol would affect the sequence of inhibiting strength of electrolytes.