ALPO4 surface processes weakly acidic AlOH and POH groups generated due to water chemisorptions on the surface. The presence of these group on were identified from the well-defined peaks in the infra red region at 510, 1000-1200, for PO bending/stretching respectively and 1650, 3400 and 3780 cm-1 for AlOH and POH, heat treatment at 300°C affects only the Bronsted acidic sites i.e., weakly acidic AlOH and POH at 1650,3400 cm1 and disappearance of the bend at 1400 cm whereas the lattice nature remains unaffected. Water adsorption again enhanced the bands at 1650 and 3400 cm-1 along with re-appearance of the band lost at 1400 cm-1.