Data pertinent to the distribution of saprophytic bacteria at various depths in the south-eastern region of the Pacific Ocean were analyzed by the method of multiple comparison. A map was constructed for the vertical distribution of the density of saprophytic microflora whose concentration in this region was lower than in other regions of the equatorial-tropical zone of the World Ocean. The incidence of saprophytic microflora was low in the surface layer of 0 to 25 m or 0 to 50 m. Five regions were outlined with a typical vertical distribution of bacterial population. A high density of bacterial population confined mainly to the layer of 25 to 300 m was observed in the region from 2 degrees s. lat. to 10 degrees s. lat., or south of 12 degrees s. lat. in water near the shore. A narrow layer with an elevated concentration of bacteria was found only at a depth of 50 to 75 m north of the equator. At a depth over 300 m, the incidence of bacteria in water was low in the whole water area; elevated bacterial concentrations were detected down to a depth of 1000 m only in the region of southern tropical divergence. West of this region, layers with a high density of bacterial population were found at a depth of 300 to 500 m and 1000 and 1500 m. The lowest concentration of saprophytes was registered in regions south of 20 degrees s. lat.