Glasses in the ternary system Cr 2 O 3-PbO-P 2 O 5 were prepared by direct melting of the mixture with stoichiometric proportions of the reagents Cr 2 O 3 , PbO and (NH 4) 2 HPO 4 at 1080˚C. The glasses obtained are transparent in colour and have a non-hygroscopic appearance. The study of the dissolution rate was carried out on ternary glasses xCr 2 O 3-(45-x)PbO-55P 2 O 5 with (1 ≤ x ≤ 4; mol%), immersed in distilled water at 90˚C for 24 days, indicating a maximum of chemical durability when the level of chromium oxide passed through 2 mol%. Both, IR spectra and X-ray diffraction have indicated the predominance of metaphosphate or cyclic metaphosphate groups with some traces of isolated orthophosphate groups when the Cr 2 O 3 content is equal to x = 2. Analysis of the density values also, has showed a maximum density for x = 2 mol%. The covalent radius values of oxygen have indicated that the minimum value rcal (O 2−) is observed for x = 2 mol% and therefore a relatively high reinforcement of the metal-oxygen-phosphorus (Cr-O-P) bonds. SEM Micrographs have exhibited two phases, a vitreous phase and a crystalline phase. The radical change in the structure from ultraphosphate Q 3 groups to ring metaphosphate Q 2 and orthophosphate groups Q 0 seems to be the cause of the formation of crystallites. Beyond 2 mol% of Cr 2 O 3 , the structure of the glass changed relatively and the orthophosphate phases increased to the detriment of the metaphosphate phases. We observed a decrease in chemical durability. However, it was confirmed that the dissolution rate (D R) of the S 2 analysed compound is comparable to the values of borosilicate glasses which are used as alternative materials for the immobilisation of nuclear waste substances.