However, a significant challenge in studying MST in liquids is the lack of a comprehensive theoretical framework to fully explain this phenomenon. While thermo-osmotic slip flow at the interface is believed to be the driving force behind thermophoresis, the complexity of nanometerscale interfaces, particularly in liquids, has led to the development of various physical models from the perspectives of non-equilibrium thermodynamics and continuum fluid mechanics. Nevertheless, no single model has yet been able to consistently explain all experimental observations. As a result, it is difficult to make rigorous predictions or hypotheses in experimental studies of thermophoresis, necessitating a trial-and-error approach under various conditions (e.g., solvent type, heating spot size, added surfactants). Moreover, even when systematic experimental data is obtained by varying parameters, the scarcity of readily available computational models hinders quantitative interpretation and evaluation. In this context, we have developed a straightforward numerical model for the MST in liquids by coupling steady-state heat conduction using the finite element method (FEM) with Brownian dynamics simulations (BDSs). As individual particle diffusion is often observed using optical microscopy in MST experiments, the results of BDSs can be intuitively compared with experimental observations. The implementation of thermophoretic forces into the BDS was carried out through two steps: (i) calculating the temperature field using the FEM, and (ii) computing the overdamped-Langevin equation using the finite-difference method. In step (i), a commercial FEM solver, COMSOL Multiphysics (version 6.2) was used. In step (ii), based on the temperature profile obtained in the FEM calculations on heat conduction, the thermophoretic force was incorporated into the overdamped-Langevin equation to numerically determine the particle motion.