Abstract:The paper deals mainly with the caloric content and its dynamics of various layer mature leaves of dominating plants in a subtropical rain forest on Hexi, Fujian. In the forest, the caloric content of dominating plant leaves in a year was as follows. In arborous layer it was 19.94～21.18 kJ·g-1 for Castanopsis hystrix, 20.34～21.33kJ·g-1 for C. uraiana, 19.98～21.04kJ·g-1 for Syzygium hancei, 21.99～23.21 kJ·g-1 for Cryptocarya chinensis and 19.17～21.08kJ·g-1 for Rhandia densiflora, respectively. In shrub layer, it was 18.45～20.20kJ·g-1 for Ardisia quinquegona, 19.18～20.04kJ·g-1 for Psychotria rubra. 17.36～ 18.47kJ·g-1 for Blastus cochinchinensis, 17.14～18.44kJ·g-1 for Lasianthus wallichii, 17.11～18.44 kJ·g-1 for Ardisia gigantifolia and 19.50～20.14 kJ·g-1 for Sarcandra glabra, respectively. In herbaceous layer, it was 18.22～19.98 kJ·g-1 for Angiopteris fokensis and 15.11～16.75 kJ·g-1 for Pronephirium simplex, respectively. In Woody liana, it was 19.73～22.57kJ·g-1 for Ecdysanthera utilis, 19.43～21.11 kJ·g-1 for Spatholobus suberectus and 18.87～20.37 kJ·g-1 for Tetrastigma planicaule, respectively. The layer mean caloric value followed the following order: arborous layer>shrub layer> herbaceous layer. The caloric value of liana was no less than that of arbor. The special organic compounds (e. g. , milk sap, oil spot and aromatic compounds, etc. )affected the caloric values of the plants, the caloric content increased when plants contained those compounds. The caloric value of fallen leaves was greater than that of the fresh mature leaves of various layer.