Since 1998, many paddy fields related to Majiabang Culture have been discovered at Chuodun site (31°24'12"N, 120°50'31.5"E), Jiangsu Province.Studies of the ancient paddy fields at the Chuodun site are of great importance for unraveling the history of rice domestication in East Asia.To further validate this site as paddy fields, phytolith and pollen analyses were conducted for P01 and P03 profiles, which are located in the northeastern part of Unit.Pollen assemblages of ancient paddy soil also were compared with those of modern paddy soil to validate the method of pollen analysis as a possible approach to-ward the ident ification of ancient paddy fields.Results of phytolith analysis show that rice cultivation activities can be traced back to middle and late Majiabang Culture, Maqiao Culture and Song Dynasty at Chuodun site.Pollen data indicate that low aquatic herb pollen corresponding to more phytoliths in ancient paddy field.Low aquatic herb pollen value is also found in modern fields.This suggests that weeds might have been removed by human during rice cultivation in the Neolithic periods.Gramineae and aquatic herbs, together with phytolith analysis, can be used as an indicator of ancient paddy fields at archaeological sites on the Yangtze River Delta.