Abstract: By means of wind tunnel simulation the wind loading on theroof of building induced by conical vortex is investigated. The pressuredistributions on the roof of the model are obtained and the mechanism of the flowis analyzed. The structure of separated flow from the roof of buildingis shown to vary with wind directions and its developing process is also analyzed.It is indicated that appearance of conical vortex is the main reason ofoccurrence of the peak suction on the roof. Results show that under certainwind directions the local time mean pressure coefficients are greater than-1.0. Moreover, the intensity of conical vortex reaches the maximum valueat the wind direction \beta =30^\circ and the time-mean peak suction andfluctuating coefficients may reach -2.4 and -5.7, respectively. It isusually the main cause of damage for the roof of buildings duringstrong winds.