Abstract: A total of 239 surface sediment samples from the Hangzhou Bay were quantitatively analyzed for foraminifera. 71 benthic foraminifera species and 6 planktonic foraminifera species have been found in these samples. The results show that foraminifera abundance in the surface sediments of Hangzhou Bay is low and the maximum only 41/g dry sample. Benthic foraminifera dominate the sample and planktonic foraminifera are rare. The foraminifera, dominated by euryhalinous and eurytopic species, are mainly re-transported allochthonous small species, such as Ammonia beccarii,Ammonia annectens,Quinqueloculia lamarckiana,Elphidium advenum,Spiroloculina communis,Pararotalia nipponica,Poroeponides lateralis. According to the distribution pattern of dominant benthic foraminifera, two assemblages recognized.