Texture is one of the most important factors to create visual realism in images. Infrared texture generation plays an important role in the field of infrared imagery simulation, and provides an effective way to satisfy the urgent need of realistic scene simulation. In order to generate realistic infrared texrtures directly in image space, a novel method for modeling and rendering realistic infrared texture of grassland was proposed. It mainly researched modeling the temperature field and the structure mophology of grassland. Firstly, the radiation transfer process in soil-vegetaion-atmosphere system was analyzed, which was expressed in the coupled infrared radiation model. Secondly, the spatial distribution pattern of grassland were simulated. Finally, infrared radiation properties were mapped to image space to generate realistic texture images. The infrared textures of grassland under close or magnification observation state were simulated. Theoretical analysis and simulation results justify the effectiveness and resonableness of the proposed method.