Abstract: The important mid-temperature thermoelectric materials Mg₂Si-based semiconducting compounds have attracted considerable interest due to their abundance, low cost and nontoxic constituents, as well as optimizable electric properties caused by tunable effective mass and mobility of carriers. This paper reviews the latest progress of Mg₂Si-based solid solutions. The methods to improve thermoelectric performance are discussed. The comparison of the advantages and drawbacks of various fabrication techniques is proposed. It is shown that, the present researches are focused on the n-type materials, and it is urgent to optimize the p-type materials properties. Doping is an effective method, and combining doping and nanostructuring through the process optimizing can further enhance thermoelectric properties.