The size and settling velocity of flocs of suspended sediments from the Chesepeake Bay were measured in laboratory experiments and in the field. The curves between floc diameter and settling velocity showed a non-Stoke's relationship that was best described by the following: settling velocity (cm/s)=1.73 (floc diameter, cm)0.78. Furthermore, the relationship between floc diameter and settling velocity indicated that the floc density decreased as the flocs increased in size. In addition to changing density, a cylinder shape was found to be the best shape factor.