Abstract: Reconstruction of three-dimensional plant morphological structure is the basis for digital plant research. In this paper, the system structure, mathematics foundation and realization process of three-dimensional geometric morphological modeling and visualization system for maize plant were introduced. The system was composed of organ geometric construction module, growth modeling module, visualization control module, database, and human-machine interface. Three-dimensional morphological structures of leaf, stem, tassel, ear, and root system were described by parameterized geometrical models based on organ morphological structural characteristics. The model parameters had definite biological background and were produced based on cultivar characteristics or growth models. During run of the system, topological structural parameters and organ geometrical model parameters were produced based on cultivar characteristics and maize growth models, and agronomical management parameters such as plant and row distance were determined through interaction of human-machine. Three-dimensional morphological structure of maize organ, plant and plant population were built on computer with VC++ and openGL. With friendly system interface, convenient operation, and easy communication, the system provided a new tool for agronomists.