Proper function of Eustachian tube is one on the main requirements for surgical tympanic reconstructions. In our E.N.T. Dept., the tubal function has been tested routinely before operation with forced positive pressure test such as Polizer, Valsalva, catheterization and negative pressure equalization test which was introduced by Flisberg(1963). We are trying to find association between the results of preoperative eustachian tube function test and preoperative conditions(presence of discharge, status of middle ear mucosa, patency of Eustachian tube) and postoperative outcome(uptake of drum, hearing gain). Following results were obtained : 1) Negative pressure equalization test of 103 patients were ; 4 in good functional group, 26 in moderate functional group, 73 in poor functional group. 2) Preoperative forced positive pressure test for 39 patients were ; 4 negative, 35 positive. 3) Among 66 patients who undergone myringoplasty or tympanoplasty type 1, 92.3% were succeeded in positive response group and 75.0% were succeeded in negative response group. 4) Among above 66 patients, 22 patients were taken forced positive pressure test. All 22 patients showed positive response and their success rate was 83%. 5) In negative response group(40 patients), 11 patients showed seromucinous discharge, while 2 patients showed scanty serous discharge in positive response group. 6) Postoperative hearing gain for 35 followed cases were;77.2±33.3% of hearing improvements for 10 cases of positive response group and 50.7±41.9% of hearing improvements for 25 cases of negative response group. 7) Among positive response group, 76.7% showed normal mucosal findings, 23.3% showed pathologic changes, while in negative response group, 30.1% showed normal mucosal findings, 69.9% showed pathologic changes. 8) With surgical microscope, all were patent except one in positive response group, while 35 cases were patent and 8 cases showed obstructive findings in 73 negative response group. 9) Eustachian tube of above 8 obstructed cases were recanalized with silastic sheet. 4 cases were successful and 4 cases were failed.