This standard specifies a technical method for the determination of calcium, mg, aluminum, nickel and manganese in rare earth ferroalloys by Inductance coupled plasma emission Light spectrum method. It is suitable for samples with a determination range of 0.0050% to 0.25%. In the method, the sample is analyzed by muriatic acid and nitric acid, excited by argon plasma in dilute acid medium, the Matrix effect is corrected by approximate matrix matching method, and then the standard Linear dispersion method is used for Light spectrum determination. This method ensures the accurate determination of trace elements in rare earth ferroalloys and helps to improve the quality control level of alloys.