Hydroxyapatite (HAp) coatings, with different surface morphologies, were formed on titanium substrates by the thermal substrate method in an aqueous solution. The coating experiments were conducted at 150 degreesC and pH = 4-8 for 20 min. The coated specimens were soaked in a simulated body fluid (SBF) at 36.5 degreesC. The in vitro HAp-inductive behavior in SBF was examined and an evaluation method for it was proposed. For the evaluation of new HAp-inductivity in SBF, a new measuring method was proposed. This did not depend on the condition of the coating, but on the surface morphology of the coated HAp.