Sulfur hexafluoride (SF 6 ), one of the most potent greenhouse gases with a global warming potential of 23 500 and an atmospheric lifetime of 3200 years, has been widely used as an insulating gas. The search for eco-friendly gas insulating medium to replace SF 6 has been a hot topic in the power industry over the past 5 years. The performance evaluation of eco-friendly gas insulating medium concentrates on several dimensions including stability and decomposition characteristics. This review focuses on recent advances in knowledge about the decomposition characteristics of eco-friendly gas insulating medium. The basic theoretical and experimental methods, discharge decomposition, thermal stability and gas-solid interface interaction properties of several potential eco-friendly gas insulating medium are summarized. The existing problems and future research directions are also discussed.