Marine biological choruses observed in Xiamen harbour from August 1981 to October 1982 lasted for a few hours each time during the neap tide in spring, summer and autumn, in both the evening and the morning, with molt energy at frequencies between 700 Hz and 1.6 kHz and spectral peaks mainly at 800 Hz, 1 kHz and 1.25 kHz.During choruses, noise spectrum levels rose up to 46 dB higher than the background noise in the sea Mate 0.The statistics of occurrence of the evening choruses indicate that they might be fairly widespread in and near shallow waters of the region.Sources of such choruses are likely to be attributed to Johnnius belengerii and Collichthys lucidus of the family Sciaenidae.