Recently, allergy to titanium has been reported. However, the patch test reagent for titanium is not standardized yet. The form and density of the patch test reagent for titanium was changed and examined in a group of normal subjects and a group with skin disease. The following conclusions were obtained. 1. A reagent which was composed of pure titanium powder and vaseline was not preferable because its form was a stimulant. 2. If the form of the titanium powder was not sharp even though it was not spherical, it did not cause a stimulated reaction. 3. It is suggested that TiCl4 0.1% is preferable as a patch test reagent for titanium.