For a typical functional space with dominant opening of a high-rise building, the distributions of mean internal pressure interference factor ( IFm) and peak internal pressure interference factor ( IFp) are studied in detail by a series of wind tunnel experiments, and the power spectrum densities are employed to present the energy distribution characteristics of the fluctuating internal pressure. For the case of windward wall opening, shielding effects are dominant for the mean internal pressures, while the peak internal pressures show certain amplification effects when the interfering building is located in the domain of {1.5 < y/b > 3} and the maximum IFp is 1.36. For the case of side wall opening, the mean internal pressures only show amplification effects in parallel arrangements for different breadth ratios ( Br). However, it is not only in the parallel arrangements but also in the oblique arrangements that the peak internal pressures show amplification effects, where the maximum IFp is 1.21 when Br = 1.0 and 1.2. With respect to the height ratio Hr = 0.6, the mean and peak internal pressures have nothing to do with the interfering building for windward wall opening, whereas they are interfered for side wall opening. When Hr = 0.8 and x/ b > 4, even though the values of IFm are less than 1 while the values of IFp are greater than 1 due to the three-dimensional flow effects.