The absorption spectra of HF-Ar mixtures have been registered in the spectral range of 30-410 cm^-1. The line asymmetry has been detected. The widths, shifts and asymmetry parameters for lines R(0)-R(9) have been obtained. The data are compared with the recently calculated lineshape parameters by Green and Hutson. The 20% discrepancy of the experimental and calculated width cross-sections is observed. The agreement of the experimental and calculated shift cross-sections is satisfactory for the lines at lower frequency but is rather poor for the lines at higher frequency. The observed line asymmetry is explained by the line mixing effect in the framework of semiclassical approach.