Abstract: Objective To investigate the factors affecting postoperative hearing in canal wall-down tympanoplasty for chronic septic otitis media(CSOM). Methods Eighty-six patients with CSOM admitted to our hospital from October 2015 to October 2017 were enrolled, who were treated with canal wall-down tympanoplasty The air conduction(AC), Bone conduction threshold(BC) and air-bone gap(ABG) between 1 week before and 6 months after surgery were compared. In addition, the relevant factors that may affect the hearing during surgery were collected. Logistic regression analysis was performed to find out the factors affecting hearing in open tympanoplasty. Results The difference of AC[(65.73±8.25)dB vs.(47.52±6.82)dB] and ABG ABG[(30.60±3.20)dB vs.(11.50±2.11)dB] between 1 week and 6 months after operation was statistically significant(t=15.777,45.122; P<0.001). The AC of the humerus or humerus floor not destroyed was better than that of destroyed. The AC of posterior tympanic opened was better than that of not opened(χ²=8.010, 7.668; P=0.018, 0.022). Whether the humerus or tibial floor was damaged or whether the posterior tympanic cavity was open were the independent factors affecting postoperative hearing in open tympanoplasty for CSOM(P=0.011, 0.014). Conclusion Open tympanoplasty has a certain effect on improving postoperative hearing in CSOM patients. Preserving the integrity of the humerus or tibial floor during operation and the open tympanic cavity are important factors influencing postoperative hearing.