In this paper, lotus-type porous Mg-Mn and Mg-Mn-Zn alloys were fabricated successfully by metal-gas eutectic unidirectional solidification (the Gasar method). Effects of elements on the mechanical properties and corrosion properties of porous Mg alloy was studied. The results showed that the addition of 1 wt.% Mn could increase the compressive strength of pure Mg from 64 MPa (porosity~36%) to 74 MPa (porosity~37%), and the compressive strength of the porous material could be increased to 115 MPa (porosity~37%) by adding 1 wt.% Zn to Mg- wt.% Mn alloy. Addition of Zn can effectively improve the corrosion resistance of Gasar Mg-Mn alloy. Conical solute enrichment area near the pore bottom of Gasar Mg-1wt.%Mn-1wt.%Zn alloy showed good corrosion resistance. Pore structure can affect the corrosion resistance of Gasar materials. When the average pore diameter was 1026 μ m, the corrosion of the pore wall in Mg-1wt.%Mn alloy was more serious. While the average pore diameter was decreased to 306 μ m, the pore of the samples would be blocked by corrosion products, and the corrosion of pore walls was less.