Abstract: Plant caloric value is the index which measures the energy utilization policy in plants. It reflects the ability of photosynthesis in green plants, and it is the basis to evaluate the efficiency of was the basis of energy fixed, energy conversion and energy utilization in ecosystem. This paper reviewed the research achievements on the plant caloric value in the succession stage of different community, in the different layers in community, in the interspecific crossing of the same forest, and reviewed the the seasonal variation of plant caloric value. Finally, this paper look into the distance to the research trend of plant caloric value.