The burning characteristics of several kinds of wood and polyurethane materials have been studied using cone calorimeter (CONE2A). A new and simple ignition criterion, heat release rate model and mass loss rate model are proposed based on experiments. Combined with these models, the zone-model of fire can be used to predict fire development in a single compartment according to the species of combustibles, their quantities and distribution. Calculated results show that this method is simple and feasible.