Abstract: The boron-lithium coordination solution was used to control the primary circuit water chemistry conditions of pressurized water reactor nuclear power plants. Under the existence of the boric acid in the primary circuit water, the lithium concentration recovery significantly decreased. In this study, we developed an ion chromatography suppressor-atomic absorption spectroscopy（ICS-AAS） online analysis system. Under the optimized conditions, the recovery of standard addition and relative standard deviations were 100% and 0.37（n=6）. The system effectively eliminates the interference of boric acid, which demonstrates that the present system can be applied in the lithium concentration analysis in the primary circuit water of nuclear power plants. The system has the advantage of simple structure, convenient operation, low cost, no pollution by the boric acid in flame atomic absorption spectroscopy, and "zero" reagent consumption.