Computational approach has been recognized as a very useful tool in accelerating the development of new materials and improvement of the existing ones. Traditional labor intensive series of experiments are greatly reduced due to the use of computational modeling tools. Implementation of such tools to improve titanium processing via parameter optimization has the potential for cost savings through the elimination of shop/laboratory trials and tests. Thermodynamic modeling tool can be used to predict phase equilibrium information given alloy chemistry, which is essential in understanding the chemical effect on the final microstructure and mechanical properties of a material. In this presentation, we will demonstrate how we can use CALPHAD approach to develop a thermodynamic modeling tool for titanium alloys. Two essentials for the successful application of CALPHAD approach: robust computer software and reliable thermodynamic databases will be discussed. The application of thermodynamic modeling tool to commercial titanium alloys, such as Ti64, Ti6242, Ti6246, Ti17 and so on, will be discussed. Some calculated examples will be presented.