The Th( n, γ) reaction cross-section at average neutron energies of 13.5, 15.5 and 17.28 MeV from the Li( p, n) reaction has been determined for the first time using activation and off-line γ-ray spectrometric technique. The Th( n, 2 n) cross-section at 17.28 MeV neutron energy has also been determined using the same technique. The experimentally determined Th( n, γ) and Th( n, 2 n) reaction cross-sections from the present work were compared with the evaluated data of ENDF/BVII and JENDL-4.0 and were found to be in good agreement. The present data, along with literature data in a wide range of neutron energies, were interpreted in terms of competition between Th( n, γ), ( n, f), ( n, nf) and ( n, xn) reaction channels. The Th( n, γ) and Th( n, 2 n) reaction cross-sections were also calculated theoretically using the TALYS 1.2 computer code and were found to be in good agreement with the experimental data from the present work but were slightly higher than the literature data at lower neutron energies. [ABSTRACT FROM AUTHOR]