The effects of environmental factors on the filtration rate of the constricted tagelus ( Sinonovacula constricta) were studied in laboratory. The results showed that the water temperature , salinity and pH had distinct effectsonthefiltrationrateoftheconstrictedtagelus. Themaximumfiltrationrateappearedattemperature 20 ℃. The filtration rate increased with the increase of salinity in the range of 6～30. It increased with the increase of p H value in the range of 6～8, and decreased at 9. The maximum appeared at pH 8.