This study built an L-system model to dynamically simulate the growth and visualize the three-dimensional structures of the rice root system using the L-studio modelling environment. Firstly, the rice root structures and characteristics in the growth processes were analyzed and several modules representing the tip of root, node of branching, node to generate the seminal root, and nodes to generate the crown roots were defined. Then, a set of production rules were developed covering the growth and branching of a single root, generation of the seminal root, and crown roots. In the model, the directions of the single root depended on two factors, a gravity factor G and a deflection factor D. They were introduced into the rice root growth production rule to investigate their influences on the growth process of the rice root system. Finally, the axiom including the notes where the seminal roots and crown root were generated was defined. With the iterative replacement of the defined modules and interpretation of turtle modules in the current strings, the continuous growth processes of the rice root system were generated. In the experiments, with the fixed parameters for the roots in different orders, the rice root system was successfully simulated and visualized with LPFG and L-studio. The experimental results demonstrated that gravity factor G determine the degree the roots bend toward the earth while the deflection factor D determine the degree the roots deflect around y axis randomly and rice root growth simulation at G≈0.3 and D≈0.3 is more realistic. This study will benefit further research on the simulation and visualization of other plant root.