The various materials as fuel are burnt in an experimental device of Room-Corridor structure, the mass loss rate of which, and the relationship of the mass loss rate with the smoke transportation velocity and CO concentration at a distant location are studied in detail in this paper. It describes the characteristics of mass loss rate of various materials and indicates that the smoke transportation velocity is a linear function of mass loss rate, and is sensitive to the variation of the mass loss rate. It takes a relatively long time for the peak of the toxic species concentration to transport to the distant location.