As the information technology develops rapidly, the software industry also keep growing and growing. Huge amount of capital and intelligence are being invested in developing the new software. However, it has been such a big negative impact on all software developers caused by the illegal reproduction and distribution. Therefore, besides the copyright regulations, software companies have always been concentrated on how to prevent their software from being illegally reproduced by adding protection codes. As most of the companies are not willing to reveal their protection methods, it is hard to have any chance to learn from each other's techniques and experiences. As a result, this thesis is really concentrated on collecting and categorizing as many as possible the protection coding technologies and in the end, analyzing and applying those to our own programs.