Using the zone-levelling technique, homogeneous alloys of the AlSb-GaSb-InSb system were obtained. The homogenized specimens were studied by means of the X-ray (Debye-Scherrer) method and differential thermal analysis. These results showed that in the above mentioned system solid solutions occur in all range of compositions. The liquidus projection of the AlSb-GaSb-InSb system and the relation between composition and lattice parameter of the AlSb GaSb-InSb section were established. Stabilities of alloys with different compositions in air were also compared.