Aerosol deposition from the plug laminar flow regime in a circular tube due to diffusion and thermophoresis is studied theoretically, and the aerosol concentration, mean concentration or deposition efficiency, and Sherwood number are calculated and analyzed by using the analytical solutions based on the detailed comparison with the previous studies. The results show that aerosol concentration distributions for both mechanisms of individual diffusion and combined consideration of diffusion and thermophoresis are symmetrical. However, the axial concentration for the case of diffusion alone is maximal, the maximal values for deposition parameter larger than zero, which appears in the region of non-dimensional radial coordinate from 0 to 1. The large influence of thermophoresis on aerosol mean concentration is found from the detailed comparison, and the bigger of the transport distance and the deposition parameter, the smaller of the aerosol mean concentration. The Sherwood number decreases with the increase of axial coordinate for deposition parameter equal and larger than zero, and the bigger of the deposition parameter, the larger of the deposition velocity.