The microstructures and mechanical properties of the recently developed Eco-Aluminum alloys were examined. Eco-aluminum alloys (based on 7050, 7075 and ADC12) are manufactured using Eco-Mg (Mg-Al2Ca) in place of Mg. Those are alloys that have economic advantage and excellent properties. Eco-aluminum alloys had smaller particle sizes compared to conventional alloys and showed evenly distributed small grains. In addition, these alloys reduced the sizes and distribution of pores and shrinkage cavities. In aluminum alloys Eco7050 and Eco7075, MgZn2 and Al2CuMg phases were distributed; in aluminum alloy EADC12, eutectic Si and Al2Cu phases were distributed. Along with this, the phase analysis verified that the Fe-intermetallic of oxide had been reduced remarkably in this alloy with the Ca addition. The result of tensile tests showed that through the Ca addition, the strengthening phases were distributed evenly in smaller sizes compared to the conventional alloys since the quantities were similar; the size and distribution ratio of porosity and shrinkage cavity also decreased. The oxides and Fe-intermetallic phases decreased remarkably as well. In the tensile tests, Eco7050 alloys showed higher tensile strength than existing alloys. Among Eco7075 alloys, T73(over aged) heat-treated ones showed higher strength than T6(peak aged) heat-treated ones. Moreover, Eco7075-T73(1.5%CaO) alloy and EADC12(0.8%) alloy with large amounts of CaO addition showed high strength values. As such, Eco7050, Eco7075, and EADC12 alloys showed higher strength compared to the existing alloys when CaO was added in proportion to the quantity added. The result of fatigue crack growth behavior tests exhibited that Eco7075-T73(1.5%CaO) alloy with high CaO contents had excellent resistance, which was deemed attributable to the evenly distributed reinforce phase. The fatigue tests were also conducted and the results showed that Eco7050[Fatigue limit: 350MPa] had the highest value followed by Eco7075-T6, T73[Fatigue limit: 400MPa, 330MPa], and EADC12(0.6%), (0.8) [Fatigue limit: 150MPa, 160MPa]. The fatigue fracture surfaces of all the alloys were observed, and all the alloys showed improved fatigue properties after the addition of CaO because of grain refinement, decreases in the sizes of precipitates, and even distribution of precipitates and reduced pores, oxides, and Fe-intermetallic phases.