Building structures are randomly distributed along the hillside, thus the detailed distribution of the topographic factor along hillside is of great importance to the wind load prediction of building structures in hilly terrain. To investigate the detailed distribution of the topographic factor along the hillside, wind tunnel tests were conducted on two hill models with different slopes, both of which were scaled to 1∶300 with a cosine section. The detailed distribution of the topography factor along the upwind slope, downwind slope, and side slope was obtained. Numerical models, which were verified by the wind tunnel testing results, were built to investigate the detailed distribution of the topographic factor of the hills with different heights (H=90~500 m), slopes (tan α=0.13~0.5), and shapes (Cosine shape, Gaussian shape, Parabolic shape).Furthermore, it was employed to deduce the calculation formula of the topographic factor, which were also compared with several national codes. Research results show that, based on the topographic factor at the hill foot and the hill top, a particular topographic factor at optional position can be obtained more safely, reasonably and simply by using vertical linear interpolation depending on the height of the calculated point rather than the horizontal linear interpolation. It was found that the topographic factor of the side slope was the control one in the prediction of the topographic factors, where the topographic factor at the foot of the side slope was respectively 61.89% and 94.09% greater than that of the upwind slope and the downwind slope, respectively, and the value reached up to 1.2.