The present study focuses on the temporal distribution of clay mineral in a new, complete type core ZX-1, recovered from the south-central Yangtze delta plain. Four diagnostic clay mineral suites are recognized from core bottom upward: Zone ; kaolinite and illite (late Pleistocene); Zone ; kaolinite and chlorite (early Holocene); Zone ; illite, smectite, and chlorite (early to mid-Holocene); and Zone V; illite and smectite (late Holocene). Holocene smectite distribution has been linked to the rapid, early Holocene sea-level rise, which induced inundation of the current delta plain. The changes in kaolinite and chlorite composition in early and mid-Holocene were apparently associated with climate oscillation as verified by pollen assemblages. Clay mineral distribution also shed light on the sediment provenance: the terrigenous sediment sources of late Pleistocene and early Holocene were primarily derived from the provincial highlands, west of the study area, and the sediments of late Holocene were basically from the Yangtze sources. The mid-Holocene clay mineral suite indicates sediment input from both the western highlands and the Yangtze sources. This clay mineral study proves potential usefulness in tracing sediment sources through time, and is certainly of significant value for better understanding the paleoenvironmental implication of the Yangtze delta evolution.