Abstract: In this paper a process for the chromatographic enrichment of uranium isotopes is studied. A hypothesis is put forward which sets forth that during the process for band displacement chromatography the isotope distribution within the band in the 235U enriched zone and the 235U depleted zone is the same as in the breakthrough and the inverse breakthrough process respectively. A concept about the calibrated plate height is introduced. Several formulas describing the relationship between some main parameters in the process for the chromatographic enrichment of uranium isotopes are derived. The experimental results are in good agreement with the calculated values by these formulas. The calculations in the process for the chromatographic enrichment of uranium isotopes are thus simplified.