The problem encountered for the extraction of structural or chemical informations from the X-ray reflectivity are as follows: One is that absorption and dispersion are mixed except for 8 >> I3 (critical angle reference Bc= 9mrad). But if 8 is very small, the mkgnitude of the signal is very weak. On the contrary for 8 N 8=, the height of the edge is large but strongly distorted by the anomalous dispersion effect. The second problem is that the absolute value of the reflectivity is unknown because of the roughnesss of the surface of the sample, together with the beam divergence which gives an overall slope to the reflectivity i.e. a pure experimental effect. Needing to study the X-ray absorption Ti K edge of the (Ti,Nb)O amorphous solid solutions, we have written a program running on I&+ PC-XT or compatible which takes into account the problems described above to correct the X-ray reflectivity spectrum in order to obtain the absorption spectrum.