The material point method (MPM) offers an effective approach for analysing large-deformation problems, such as landslides that often involve unsaturated soil[1]. Several MPM formulations for unsaturated soil have been reported in the literature, but they assumed that soil water retention ability and permeability function are independent of soil deformation[2]. Furthermore, most studies assumed isothermal conditions, although friction-induced heating of the shear band could greatly affect the behaviour of unsaturated soil. To address these problems, a thermo-hydro-mechanical coupled MPM formulation has been developed based on the two-phase two-point framework. The information of solid and liquid phases is carried by two individual sets of material points, assuming zero air pressure. The MPM formulations consider the effects of porosity and temperature on the water retention curve and permeability function of unsaturated soil. The elastoplastic mechanical behaviour is modelled by the Drucker-Prager model, which is modified to consider shearing-induced dilation/contraction, suction and thermal effects. Friction-induced heating and its influence on soil behaviour are incorporated. The MPM simulations were compared with the results of physical model tests (for large-deformation problems) and finite element analysis (for small-deformation problems). It is evident that the proposed MPM formulation is able to model various thermo-hydro-mechanical problems well in isothermal and non-isothermal conditions. In particular, the computed failure processes of unsaturated soil slope under rainfall are consistent with results from physical model tests.