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Measurements of the vertical concentration profile of deposited Pb and its parent (Ra) in cores of recent marine sediment of Mumbai Harbor Bay (MHB) were made to determine the various depth distribution parameters (sedimentation rate, age of sediment, total inventory, fluxes, residence times, scavenging rate, linear attenuation coefficient and relaxation mass depth). Overall, the profile distributions of Ra and Pb showed a decreasing trend with increasing the depth. The mean of sedimentation rate in the studied area was obtained to be about 0.76 cm year which corresponds to average age of sediment of about 56 years. The average total deposited Pb for the studied sediment profile was 9.68 k Bq m and correspondingly the average value of fluxes of total Pb and excess Pb (atmospheric flux) were 0.59 and 0.32 k Bq myear, respectively. The residence time of Pb was in the range of 26-226 years throughout the sediment profile and showed generally an increasing trend from top to bottom. The mean relaxation mass depth (h) derived from the depth profile of Pb at the studied area was about 190 kg m. The negative association between clay content of cores and the h of Pb indicates that as the clay content increases, the penetration depth of deposited Pb in sediment profile decreases. [ABSTRACT FROM AUTHOR]