Abstract: In order to study the interaction between the internal pressures and external pressures on cooling tower,a wind tunnel model was made which can make possible the simultaneous measurement of internal and external pressures.The distribution of internal and external pressures under different surface roughnesses is investigated.The difference between the models with and without A-shape columns in the bottom is analyzed.Then the difference of the mean wind-induced responses considering and disregarding the internal pressures is also investigated.Results from study show that,if the model surface is smoother,the maximum negative external pressures are bigger.The models with and without A-shape columns in the bottom have significant difference of the internal pressure coefficients,whose mean values are about-0.4 and-0.7,respectively.The internal pressure can be approximately considered as even pressure,which will result in the circumferential membrane stresses of cooling tower.