Optimization of capital structure has been a famous issue in Corporate Finance. It is essential for modern companies to find the optional capital structure of themselves because it could help these companies to reduce the cost of finance. This best structure is not easy to find out due to the complex determinants behind it. However, there still are some alternative ways could be used to judge whether a company reach its optional capital structure. This report takes X company as an example to discuss that how to use different efficient methods to estimate the optional capital structure of a company.