This study evaluated the toxicity of the sediment on 7 points located in front of drainage canals river on the beaches of Santos-SP, together with the characterization of the community structure of benthic macrofauna. Were performed campaignsummer (February 2008) and the campaign winter (July 2008). The toxicity tests with sea-urchin Lytechinus variegatustreatments were performed in elutriate and sediment-water interface, as ABNT NBR 15350/2006. The benthic macrofaunawasidentified as Mollusca, Crustacea and Polychaeta, and it was calculated mean density (ind/0,026m²) and Polychaetadominance. In campaigns for summer and winter treatment sediment-water interface showed toxicity at all points, whilethe treatment elutriate showed toxicity at points 6 and 7. Polychaeta dominance was negatively correlated (r = -0,56) withgranulometry and positively correlated with organic matter for the winter campaign, being some of these species indicators.of polluted and anoxic environments