In order to clarify characteristics of temporal-spatial flow structures above and wind pressures on the roof of a cubic structure, a wind tunnel experiment was carried out in two types of turbulent boundary layers. The flow was measured by Particle Image Velocimetry (PIV) system and simultaneous multi-pressure measurements on the surface were also performed. The time-averaged separation bubble on the roof had flat shape with a gradual curvature. When the intensity of turbulence of the approaching flow was large, and strong local negative pressure was generated in the windward edge corner, a flat conical vortex was formed, and the spatial structure of the flow was different from the time-averaged flow.