The density dependence of the line shift of the cesium D2 line is studied with sub-Doppler selective reflection spectroscopy. By use of wavelength modulation and sixth-harmonics detection we observed the coefficient of the pressureinduced shift of the 6S1/2(F=4)→6P3/2(F＇=3) hyperfine transition of the cesium D2 line △δ/p=-0.9(5)×10-8cm3.In the limit ρ=0 a frequency shift about -3MHz remains, which may be attributed to long-range atom-surface interactions. The experimental results can be used in measurements of the local field-induced frequency shift at high atomic densities with sufficient accuracy.