Abstract: A method for the determination of high content sulfur in copper sinters by high frequency-infrared carbon-sulfur spectrometry was presented in this paper. The analytical conditions such as sample weighting amount, flux types, loading sequence and quantity, etc. have been tested. 60-120 mg of sample mixed with 0.4 g of pure iron filings and 1.3 g of tungsten pellets in a ceramic crucible was melt by a high frequency furnace and the carbon and sulfur in the sample was then determined. The concentrations of sulfur determined by this method range from 1%-23%. The recovery is between 94% and 113%, and RSD is less than 2%. Comparing with the routine gravimetric method of BaSO₄, this method provides more reasonable results for copper sinters with RE less than 4%. This method has been applied to practical sample analysis for rapid and accurate determination of the high content sulfur in copper sinters.