Objective: To decided the effectiveness cochlin-tomo-protein (CTP) detection in classifying the labyrinthine fistula.Methodology: Between March 2012 and November 2013, 9 patients were diagnosed as having labyrinthine fistula during the cholesteatoma surgery.In 4 patients, the size of the fistula was smaller than 2 mm (including 1 patient with preserved thin bone over the fistula: blue-line).In the other 5, the size of the fistula was larger than 2 mm.In all patients, the matrix of the cholesteatoma over the labyrinthine fistula was removed with a knife, with a meticulous effort to preserve the endosteum.After removing the matrix, the fistula was rinsed with 1 ml of saline.CTP in the rinsed saline was analyzed by the Enzymelinked immunosorbent assay (ELISA).