Abstract: According to tomato's structural characteristics and its developmental rules of morphology,a dynamic and stochastic architectural model was set up by applying the theory of finite state automation.By the investigation on the real plant,four macro-levels were abstracted to describe the architecture of tomato,and two fundamental concepts,namely physiological age(PHYAGE) and growing age (GA),were proposed to simulate its growth,branching and death process.Binomial law was used to model the stochastic number of nodes on some growth axis.Markov process was explored to simulate its ramification pattern.With the parameters got from the experimental data,the architectures of tomato at different stages were reproduced.This dynamic model will provide a basis to interface with function-oriented model in order to set up an interactive structural-functional tomato model for the further study.