The methodology proposed in the paper applies artificial intelligence (AI) techniques to the modeling and simulation of the plant growth. Because it is difficult to build up the production rules, a new construction method of L-system was proposed, which applied fuzzy reasoning to build up the production rules based on language description of plant growth. This method built up related fuzzy sets, and then constructed the L-System production rules by fuzzy reasoning. The rewriting of module string and construction method of production rules was also introduced. Combined with co2 concentration in the plant growth circumstance, the process of plant growth was simulated. The simulation result is agree well with a general rule of the plant growth, which shows that the method of L-system base on multi-dimensional fuzzy reasoning can simulate the process of plant growth in a given circumstance without the difficulties brought by parameter setting in mechanistic model .