To investigate the effects of depth-to-width ratio on the aerodynamic admittance of wind loads on rectangular high-rise buildings, wind tunnel pressure tests for high-rise buildings with depth-to-width ratios of 0.11[WT5,6”BZ〗 — 9 were conducted. Patterns of the aerodynamic admittances for fluctuating wind pressures on each wall and base drag were investigated under the orthogonal wind direction, which were then compared with quasi-steady assumption based Vickerys model and Solaris model. Closed-form expression for the aerodynamic admittance for base drag of buildings with different depth-to-width ratios was obtained through fitting analysis. Results show that when the depth-to-width ratio is lower than 0.5, the aerodynamic admittances for base drag and fluctuating pressures on the windward wall are close to Vickerys model.But as the ratio increases, the decay rate of the aerodynamic admittance becomes lower, and Vickerys model and Solaris model are significantly lower than the measured values.On the leeward and side walls, due to the effects of body-generated turbulence such as flow separation, reattachment, and vortex shedding, peaks with different sizes appear at high frequencies of the aerodynamic admittances for fluctuating pressures, where the varying pattern and magnitudes of Vickerys model no longer match. The fitted formula in power function form that obtained in this paper can well predict the aerodynamic admittance for base drag of rectangular buildings with different depth-to-width ratios.