Abstract: For the demand of heat exchange research between plant and its environment, especially the need of organic Thermophysical parameters in the analysis of ecology, the paper studied the specific heat of plant organs using the heat balance method. Tomato leaves and fruits were selected for measurement. The pioneer tree of ecological recovery, arborvitae, and the fleshy plant, aloe, were also taken as the objects in this study. The results showed that the specific heat of tomato leaf was (3253.7±97.10) J/(kg℃), which was approximate with those of the arborvitae and aloe. The specific heat of tomato fruit was (3517.4±68.50) J/(kg℃). The specific heats of plant organs mentioned above could be measured by heat balance method, and all the specific heats measured in this study were lower than the specific heat of water. This paper also consummated the heat balance method in organic specific heat measurement. The research can provide a new method for specific heat measurement and a basis for plant heat exchange research also.