Directional solidification of metal-gas eutectic (Gasar) is a novel process for making regular porous metals.This process is based on a solid-gas eutectic reaction involving a gaseous medium and a metal or a ceramic phase, and allows an easy control of the porosity, such as its pore size, pore orientation and morphology in a wide range by properly adjusting its melting and solidification conditions. The latest progress and our research work in this field are reviewed in this paper.