Abstract: Atomic concentration profiles of components and contaminants in foils were observed with elastic recoil detection analysis technique. High quality heavy ion beam~(127)I provided by HI-13 tandem accelerator of CIAE was used for the measurements. Elements from H to medium heavy were simultaneously measured by a ΔE-E(PSD) telescope. The depth resolution of 20～30 nm was obtained. A depth resolution of nano- (meter) level was achieved at the surface of thin foils by a Q3D magnetic spectrometer and the focal plane detector with its momentum analysis. The developed technique is useful in the measurements of multi-layers films with the thickness of nanometer.