A chemiluminescence emission between TiO2 nanoparticles(NPs) and Fe2+ in the air was observed.The chemiluminescence intensity could be enhanced in the presence of cetyltrimethyl ammonium bromide(CTAB).Moreover,the CL intensity of Fenton chemiluminescence reaction of Fe2+ with H2O2 could also be enhanced by TiO2 NPs.Based on this,a new chemiluminescence method for the detection of Fe2+ was developed.Under the optimal conditions,the calibration curve was linear in the range of 1.0×10-8 -1.0×10-6 mol/L with a detection limit of 4.0×10-9 mol/L.The relative standard deviation(n=5) for 1.0×10-7 mol/L Fe2+ was 3.9%.A brief discussion on the possible chemiluminescence reaction mechanism was also presented