A shoe tree for one shoe includes a main body having a front end formed with a vamp support portion and a rear end formed with an upwardly extending rising portion and having a first side formed with a first side support portion and a second side formed with a second side support portion. Thus, the first side support portion has a shape matching that of the outer side of the shoe, and the second side support portion has a shape matching that of the inner side of the shoe so that the inner space of the shoe is supported by the main body of the shoe tree rigidly and stably, thereby preventing the shoe from being deformed due to its gravity.