【Abstract】 Objective To investigate the changes of middle ear function and the status of tympanic ventilationtube after tympanic ventilation tube in chronic otitis media in 3～6 years old children.By studying the wideband acoustic immittance(WAl-0 daPa)curve.Methods A total of 71 children(121 ears)were included with 20 ears for normal middle ear function group,20 ears for chronic otitis media group,19 ears for 0～1 month after tympanic ventilation tube group,19 ears for 3-month group,17 ears for 6-month group,19 ears for 12-month group,7 ears for blocking tympanic ventilation tube group.Wideband acoustic immittance test was performed and recorded at 107 frequencies between 226 to 8000 Hz under ambient pressure(0 daPa)conditions.Kruskal-WallisH and Nemenyi analysis were used to analyze the effects of middle ear functional status,tympanic ventilation tube placement cluration,and ventilation status on WAl-0 daPa.Results ① Except 226 Hz and 5 339 Hz,WAl-0 daPa in tympanic effusion group was significantly lower than that in normal middle ear group.WAl-0 daPa at 226～667 Hz and 1 000～1 297 Hz in0～1 month group was significantly higher than that in the group with normal middle ear function group.Except for 4000～5339 Hz,WAl-0 daPa at all frequencies in tympanic effusions group was significantly lower than that in the 0～1 month group.② WAl-0 daPa at 500 Hz and 3664 Hz in the 0~1 month group was significantly higher than that in the 3-month group.WAl-0 daPa at 1682 Hz was significantly lower than that at 6 months.WAl-0 daPa in 2 670～3 364 Hz was significantly higher than that in 6 months group.At 226～324 Hz and 2 670～4 000 Hz,WAl-0 daPa was significantly higher than 12 months.WAl-0 daPa at 1 297～1 682 Hz wassignificantly lower than that at 12 months.WAl-0 daPa at 5 339 Hz in 3 month group was significantly higher than that in 12 month group.③ WAl-0 daPa at 226～667 Hz in 12month group was significantly higher in the group with normal middle ear function.At 2 670～5 339 Hz,it was significantly lower than that of normal middle ear function group.At 226～500 Hz and 1297 Hz,the WAl-0 daPa in blocking tympanic ventilation tube group was significantly lower than that in the 12 months group.Conclusion WAl-0 daPa in chronic otitis media children was significantly lower than normal middle ear function children.The tympanic ventilation tube significantly increase WAI-0 daPa in chronic otitis media children.Using WAl-0 daPa can provide objective reference for status of tympanic ventilation tube.