The wind pressure time history records of the annular cantilever roof were obtained by the synchronous wind tunnel test on a rigid model of a stadium. Considering the influence of the vortex shedding, the correlation coefficient and coherence function of along wind and cross wind points were analyzed to get the characteristics of the external fluctuating pressure correlation of the stadium's cantilever roof. The coherence function curves were fitted and the related coherence function was presented. Compared with the classical coherence function models, the present coherence function has the same form and a higher fitting accuracy for the cantilever roof.