The palygorskite was ion-exchanged with NbCl5 and calcined at 300°C to prepare solid acid of palygorskite supported Nb2O5 (300-Nb2O5/PG). This modified palygorskite was characterized by XRD, XPS, UV–Vis, N2 adsorption/desorption, ICP and NH3-TPD. The material was used in the esterification of trioctyl trimetabenzoate (TOTM) as catalyst. The esterification yield of trioctyl trimetabenzoate was 95.3% at 210°C to reflux 5 h when catalyst amount was 5 wt. % of trimellitic anhydride, trimellitic anhydride: 2-ethyl hexanol = 4:1(mol/mol). The esterification yield was 89.2% when the catalyst was reused ten times.