Objective To analyze the influence of round window lesion on dynamic responses from the middle ear. Methods Based on CT scan images of healthy human ear, the three-dimensional finite element model of human ear was rebuilt by PATRAN software, then NASTRAN software was applied to conduct coupled solid-fluid frequency response analysis. The feedback of round window lesion on dynamic response of the middle ear was investigated by numerical simulation. Results Round window closure caused by sclerosis led to more decline in amplitude of stapes than congenital round window closed, maximally can reach 30.2 dB, and the latter had no obvious influence on velocity of stapes. In term of phase angle, on condition of sclerosis, change of phase for stapes and round window reached 90° at most and kept a difference value of 180°. In contrast, on condition of congenital round window closed, change of phase for stapes reached 270° at most，meanwhile change of phase for round window disappeared. Conclusions The dynamic response of the middle ear showed different feedback to congenital and otosclerotic round window fixation based on amplitude, velocity and phase. The research findings provide the theoretical basis for diagnosing and fixing round window lesion in future.