Applied graphite furnace atomic absorption spectrometry to determine barium ion of Xiangjiang River. The experimental results showed that the detection linear range is 0~40 g/L with adding standard recovery of 94%~98% and relative deviation less than 5%. The detection limit is 0.022 g/L, which is much lower than the national standard limit of 0.7 mg/L for surface water. Proved that the method can be used to determine barium ion in Xiangjiang River.