The electroless nickel plating of as-cast AM60B magnesium alloy was carried out using NiCO3·3Ni(OH)2·4H2O as main salt and sodium hypophosphite as reductant. The influence of pH value on the microstructure, microhardness and electrochemical properties of the electroless Ni plating was studied using X-ray diffractometer (XRD), microhardness device, metallograph and electrochemical station. The results show that the deposition rate of the electroless Ni plating increases when the pH value increases from 6.0 to 7.0. The electroless coating is composed of cell structures. When the pH is 6.5, the electroless Ni coating is compact and the particle is smallest. The microhardness and the P content are reduced with the pH value increasing from 6.0 to 7.0. When the pH value is 6.0, the microhardness HV is highest and gets to 5400 MPa. At the three pH values, the electroless Ni coating is integrated; the main peak of Ni is wider, while there are nearly no second or third peaks. When the pH value is 6.5, the corrosion electric potential of plating is up to –0. 90 V, and the corrosion resistance is best.