This paper presents a survey of the geometrical shapes of atrium in China mainland. The types of atrium are classified according to their geometry aspect factors. An experimental reduced-scale compartment, which is a 1/8-scale modeling of a full-size atrium, is established. The experiments of smoke filling and mechanical exhaust during atrium fires are conducted. Based on experimental data, an equation for predicting the position of the smoke layer interface for high type atrium with steady fire during smoke filling, and an equation for predicting plume mass flow rate, which shows the characteristic of confined plume, are obtained. Research results were applied to predict the position of the smoke layer interface and smoke plume mass flow rate for high-type atria.