Desertification is one of the most serious ecological/environmental problems in arid/semi-arid region. However, we have less knowledge on the growth of key plant species grown in desertificated area. In the present researches, we aim to clarify morphological and eco-physiological characteristics of some key species by environment-controlled growth experiments and to develop an individual-based “functional-structural growth model” of each species which responds to environmental changes usung “Lindenmayer system (L-system)”. Basic structure units of each plant were analyzed using real plants cultivated under normal environmental condition, collecting above/below-ground plant parameters such as stem length, number of leaves, root length, angle of rooting direction, etc. Then we tested a performance of the model, and confirmed that our model has a potential to simulate 3-D above/below-ground growth of species grown in arid/semi-arid region. We developed models of Artemisia halodendron, Caragana microphylla and Cleistogenes squarrosa not only under normal condition but also under water stressed condition.