Simulated terrains have been extensively used in many flight simulators or games. unfortunately, creating large terrains can be considered tedious and complex job. therefore some flight game makers only created a limited amount of terrain and raused the same terrain for onther level of the game. though it seems solving the problem, increasing the number of terrains used in the program may make the game becomes more interesting. since terrain actually is a fractal, the terrain can be generated using the concept of tractal. the resulted terrains can be saved in a text file to be utilized by any other programs. this research has overcome the terrain creation problem by generating user-defined terrain automatically.