Plant canopy temperature and soil temperature can be used to estimate canopy transpiration. The sensible heat flux and latent heat flux of the soil are crucial in predicting drought and estimating crop yield. In reality

land vegetation has multiple types with different shapes and spatial distributions; thus

a general model suitable for variety of vegetation types is important to investigate the thermal radiation directivity of the surface covered by vegetation. Based on the theory of bidirectional gap probability

a three-dimensional simulation model for hermal radiation directivity of a nouniform canopy was established in this study. The ideal plant given the special distribution was employed to form the canopy observation scene. The ideal plant is the basic unit for describing the observation scene

which possesses the statistical averages of the parameters of all the plants in the observed area. The multi-angle thermal infrared field data of different growth periods of a corn crop was used to verify the results of the simulation model proposed in this paper. Encouraging results have been obtained. The results show that the model can accurately simulate the change trend in the canopy temperature distribution with only a small deviation

which may be attributed to the following factors:（1） The deviation in the parameters used to establish the ideal plant affects the simulation result.（2）The roughness of the soil layer and the shape of the leaf are not considered in the process of simulation.（3） The model does not consider multiple scattering in the canopy body. Moreover

the quantity of the plants in the observation area is limited

and the spatial distribution of the plants differs to a certain extent from the statistical average used in the simulation. Given the parameters of the ideal plant and its spatial distribution

the model can calculate the area ratios of the four components in asparse vegetation scene

dense vegetation scene

and a mixed vegetation scene. The results combined with the Li-Strahlergeometric-optical model could be applied to the study of the surface albedo under complex surface conditions.