Chlorine and iodine in the air from oxygen-iodine chemical lasers have been determined simultaneously.Sodium sulfite solution is used as absorption solution.Sampling efficiency is determined by a series two-stage absorption tubes.Chlorine and iodine are simultaneously collected by air sampler with multi-hole absorbing tubes.The concentrations of Cl-and I-in the absorption solution are detected by ion chromatography.When 15 L air is collected using 10 mL absorption solution at a flow rate of 1.0 L/min,the sampling efficiencies are 99.4%±0.3% and 99.7%±0.1% for chlorine and iodine,respectively,and the detection limits are 0.019 mg/m3 and 0.030 mg/m3.The expanded uncertainties are 8.2% and 6.3% when P=0.95.In the five monitoring sites of experiment place,the highest concentration of chlorine is 0.200 mg/m3.The concentration of iodine is lower than its detection limit,but both of the chlorine and iodine concentrations are lower than their maximal acceptable concentrations(1 mg/m3) in the air of workplace,and these data provide an important evidence for estimating the harm to staff.This method is with simple operation,fast detection and little interference,and also could be used to determine the chlorine and iodine in the air of ambience and workplace.