Objective To investigate the aerodynamic characteristics of vocal polyps and vocal nodules.Methods Aerodynamic parameters of 58 patients with vocal polyps or vocal nodules and 30 normal adults were measured by Aerophone Ⅱ Voice Function Analyzer.The mean airflow rate,intraoral pressure,glottal resistance,glottal efficiency were compared among different group.Results The mean airflow rate,glottal resistance and glottal efficiency of vocal polyps,vocal nodules and normal adult were 254.50±36.02 ml/s,33.55±4.63 cmH_2O/(L·S),2.46±1.49,177.45±25.93 ml/s,38.83±8.88 cmH_2O/(L·S),7.75±3.71,118.44±29.98 ml/s,53.04±8.64 cmH_2O/(L·S),9.17±3.87,respectively.The difference between them was significant(P＜0.01).The difference of intraoral pressure between vocal polyps (8.97±1.36 cmH_2O) and normal adult (6.24±0.99 cmH_2O) was significant (P＜0.01).The mean airflow rate,glottal resistance,glottal efficiency were significantly different between vocal polyps and vocal nodules(P＜0.01).Conclusion The degree of vocal fold adduct and the effciency of voice production in vocal polyps is worse than that of vocal nodules.The aerodynamic parameters can make quantifiable,objective assessment in voice function of vocal polyps and vocal nodules.