As a surface modification technology of titanium and titanium alloys having aroused wide concern, thermal oxidation features in simple process, in situ growth, thick oxide coating and high cost performance. Thick hard oxide film consisting of Ti oxide layer and oxygen diffusion layer was formed on the surface of Ti and Ti alloys by virtue of thermal oxidation surface treatment technology. The oxide film could protect materials effectively and also improve single wear resistance, corrosion resistance and biological activity or comprehensive surface properties significantly. Research progress regarding effects of thermal oxidation on properties of Ti and Ti alloys (surface hardness, wear resistance, corrosion resistance, biological biocompatibility, etc.) was summarized from the perspective of thermal oxidation process principle and its effect on surface properties of Ti and Ti alloys. In addition, the research trend was expected. Continuous and compact hard oxide layer consisting of rutile and oxygen diffusion layer of good fatigue performance was obtained by controlling such process conditions as oxidation temperature, oxidation time, oxidation atmosphere and cooling mode properly. Such an oxide layer was the key to improve properties of Ti and Ti alloys. The research direction of thermal oxidation in improving properties of Ti and Ti alloys is preparing composite coatings by combining thermal oxidation with other processes and being targeted to improve film thickness as well as wear resistance, corrosion resistance and biological properties of materials.