Abstract:High frequency infrared carbon and sulfur analyzer is convenient and efficient, so most widely used to measure sulfur content in regional geochemistry samples. The determination of sulfur in rock, soil and stream sediments by High frequency infrared carbon and sulfur analyzer. The conditions experiments were optimized by comparing the sample weight, sample and flux stacking order, and flux amount. The experimental method was verified by national first-level reference materials. The results show that when the stacking order and quality of the sample and the flux are: 0.5 g pure iron, 0.05 g sample, 1.7 g tungsten tin, the determination result of sulfur is ideal in Soil and stream sediment, and 0.5g of tin was added to rock samples to improve the fluidity of samples and improve the accuracy of analysis. The precision of the method (RSD) is less than 9%, and the absolute value of relative error was less than 8%. This method is characterized by simple operation, high efficiency and stability, and is suitable for for the detection of sulfur in a large number of multi-target chemical samples.