Objective: To analyze the clinical characteristics, curative effect related factors and follow-up situation of bilateral sudden sensorineural hearing loss (BSSHL). Methods: The clinical data of 169 patients(338 ears) with BSSHL were retrospectively summarized, and the demographic characteristics, predisposing factors, concomitant symptoms and diseases, and audiological characteristics were statistically described. Additionally, influencing factors of curative effect and prognosis were statistically analyzed. Results: Among the 169 patients, 50.9% (86/169) of patients had at least one incentive, with cold and fatigue being the most common incentives(both 23/169). There were high rates of accompanying symptoms including tinnitus (150/169, 88.8%) and dizziness (100/169, 59.2%). Hypertension(49/169, 29.0%)and diabetes(23/169, 13.6%)were the most common concomitant diseases observed. Most cases exhibited all frequencies involvement, with flat type and total deafness type accounting for 83.1%(281/338 ears). The most common degree of hearing loss was total deafness(86/338 ears), with approximately 60.1%(203/338 ears) of the cases being severe or worse. The total effective rate of treatment was only 29.0%, but it increased to 39.5% for patients with course of disease≤14 days, however, when course of disease>30 days, the effective rate decreased sharply to 3.6%, showing a significant difference between these two groups(χ2=13.776,<0.01). Different types of hearing curves showed statistically significant difference in efficiency(χ2=14.782, P<0.01). Comparing the hearing improvements of 28 BSSHL patients from admission to discharge and from discharge to follow-up, it was found that the hearing improvement of the two groups showed statistically significant difference at the frequencies of L-250 Hz, L-500 Hz, R-125 Hz, R-250 Hz and R-500 Hz(Z value was -2.495, -3.083, -3.970, -3.388 and -3.264 respectively, all P<0.05). The proportion of patients with elevated serum IgE was much higher than that of the normal population. Conclusion: BSSHL patients suffer from serious hearing loss, and many also experience tinnitus and vertigo symptoms. Due to the poor efficiency of treatment, it is better for patients to be treated within 30 days of onset. For patients of hearing loss in the low frequency range, hearing improvement is more significant during hospitalization. And the occurrence of BSSHL may involve an immune mechanism.