Abstract: For the chloridetype brine from the Charhan salt lake of Qinghai province, lanthanum chloride was used as coprecipitator in hydrochloride medium for separation and preconcentration of available selenium in brine samples and available selenium was then determined by hydride generationatomic fluorescence spectrometry. The detection limit of method is 0.008 μg/L for selenium with linear dynamic range of 0～100 μg/L and standard addition recovery of 97.5%～101.9%. The method has been applied to the determination of available selenium in chloridetype brine samples and has been proved to be accurate and reliable.