Directorate of Geology and Mining, 63-B, Stainly Road, Allahabad-211 002, Uttar Pradesh, India E-mail : sushill010@rediffmail.com Chemical Laboratories, Department of Chemistry, University of Allahabad, Allahabad-211 002, Uttar Pradesh, India E-mail : mcc46@rediffmail.com Manuscript received 21 August 2006, accepted 11 September 2006 Natrolite (Na2O.AI2O 3.3SiO2.2H2O) was synthesized using hydrothermal apparatus at temperatures 200, 250, 300 and 350 °C and pressures 500 bar and 1000 bar. It was observed that the extent of formation of natrolite, as revealed by X-ray diffraction studies, increases with pressure in the temperature range 200 to 300 ºC and then it decreases.When the pressure was kept at 750 bar and temperature varied from 225 to 275 ºc,the extent of natrolite formation increases linearly. The percentage of crystallinity was also calculated from X-ray diffraction data. The FTIR spectra of synthesized natrolites at different temperatures and pressures were recorded by KBr wafer technique and different bands have been assigned.