Provided is a tree model generating method according to an embodiment of the present invention. The tree model generating method includes separating and extracting a skeleton of a tree from an image including the tree to generate a matte image, applying a graph representation scheme of a two-dimensional (2D) object to the matte image to generate an object skeleton graph, generating a depth information value in accordance with a predetermined rule and allocating the generated depth information value to each node on the object skeleton graph to generate a three-dimensional (3D) primary tree model, adding branches to the primary tree model based on a branch library constructed in advance and the predetermined rule to generate a secondary tree model, and performing self-growth representation with respect to the secondary tree model based on a distance between each node on the object skeleton graph to generate a tertiary tree model.