Line intensities of the ClO radical in the fundamental vibrational band, v=0--1, have been measured using a high-resolution Fourier transform spectrometer coupled to a long path length absorption cell. The ClO infrared absorption spectra were recorded at 0.004 cm-1 unapodized resolution in 50 coadded scans at total pressures less than or equal to 0.4 Torr, He buffer gas. Spectra were recorded at calibrated over the range 4¿1012 to 1.4¿1013 molecule cm-3, using two different chemical sources of ClO:Cl+O3 and NO+OClO. The band intensity was measured as S=9.68¿1.45 cm-2 atm-1 (95% confidence level) at 296 K, which is in agreement with a recent ClO band intensity determination using the concentration independent Herman-Wallis method of band intensity analysis (Burkholder et al., 1987a). This value of the ClO band intensity is a factor of 2 greater than the value recently reported by Kostiuk et al. (1986). A N2 collisional broadening coefficient of &ggr;0=0.093¿0.018 cm-1 atm-1 (95% confidence level) was determined from spectra recorded with 10 torr N2 added. A source of systematic error in the use of the Cl+O3 reaction as a quantitative source of ClO radicals is discussed. ¿ American Geophysical Union 1989