Abstract: Through the sediment particle size experiment of 38 sample from QTZ1 drilling of lower pleistocene in Wenzhou Oujiang estuary, get the sediment particle size parameters, cumulative frequency curves and cumulative probability curves of the early pleistocene in study area. The frequency distribution curve of grain size is mainly single peak, and there are a small number of hump pseudo-unimodal and bimodal curve. The probability accumulation curve is dominated by coarse grain. The sedimentary environment of the quaternary early pleistocene(1.072-1.778Ma BP)was discussed based on the analysis of the ancient geomagnetic data and the existing geological data in Wenzhou. Analyzing the characteristic of particle size and the results reflect the Wenzhou region Oujiang estuary coastal zone during the early pleistocene sedimentary hydrodynamic condition is relatively low and relatively stable, the sedimentary environment of lower update for fine silt and clay level alluvial-sea environment, local development large-scale transgression.