The complexity and diversity of microstructural information involved in Ti alloys makes it rather difficult to quantitatively analyze properties or describe microstructural evolution behavior. Feasible and rigorous models capable of quantifying various microstructural data are rarely researched. Based on metallographical characteristics and mechanism of microstructure evolution, applying the stereology and quantitative Metallography rules, a preliminary system of models and methods for quantifying many important microstructural features of Ti alloys was developed. The work is an exploration for investigating the microstructure evolution and the relationship between microstructure and performance of Ti alloys. These microstructural features mainly include phase volume fraction, β grain size, thickness of Widmanst?tten α laths, colony size, and α phase information (size/orientation/aspect) in some microstructures. Six rules for manual-splitting α phase on image processing was presented. These models and methods are feasible, and explained with some examples