Abstract: The objective of this experiment is to quantify the leaf extending character and provide methodological support for morphogenesis simulation model in super-maize, which the cantilever beam theory was used. The same leaf was divided into many basic units, and each basic unit represented a cantilever beam. The simulation model of leaf extending in super-maize during the whole growth phase was developed. The observed data on super-maize leaf in different population were used to verify the model. The results show that RMSE of extending coordinate of different leaves were less than 30%, and the 80% predicted D value was greater than 0.7. So the model has a better simulation of the leaf extending character in super-maize and the method using the cantilever beam in simulation of super-maize leaf extending character is feasible.