In order to find good candidate materials for degradable fracturing ball applications, the microstructure, mechanical behavior and corrosion properties of as‐cast Mg‐17Al‐3Zn‐xCu alloys were investigated using optical microscope, scanning electronic microscope equipped with energy dispersive spectroscope, compression tests, electrochemical measurements, and immersion tests. The results show that Cu addition affects not only the amount but also the morphology and distribution of T‐phases. The distribution of Al also has a large dependence on Cu concentration. These modifications of the microstructures accordingly affect the mechanical and corrosion properties of the investigated alloys. Mg‐17Al‐3Zn‐5Cu alloy can be used as degradable fracturing ball.