Species specific cell adhesion in marine sponges is mediated by proteoglycans composed by sulfated polysaccharides attached to a protein core. In the present work we determined the cellular location of sulfated polysaccharides in cells of the marine sponge Hymeniacidon heliophila and the effects of different sulfated polysaccharides in the sponge cell culture. Tissues of H. heliophila were dissociated using CMFSW + E (calcium magnesium free seawater + EDTA). The cells were stained with Toluidine Blue 1% pH 4.4 for the identification of sulfated polysaccharides by the characteristic metachromasy produced by the dye. All morphologically distinct cell types observed in H. heliophila display strong metachromasy in the cell surface and six of then also exhibited metachromatic intracellular vacuoles. Cell suspensions of H. heliophila were incubated with different media: FSW only (filtered seawater with antibiotics, sterilized by filtration in 0.22mm cellulose acetate filters. Control); FSW supplemented with purified sulfated polysaccharides from the sponges H. heliophila (different concentrations), Dysidea robusta (3mg/ml) and Aplysina fulva (3mg/ml); and FSW supplemented with Heparin (different concentrations). After 12 hours of incubation, the areas of H. heliophila cell aggregates were measured (mean and SD) and compared by the statistical test ANOVA. The aggregates areas in the cell cultures incubated with sulfated polysaccharides from D. robusta and A. fulva showed no significant differences with the control. However, the addition of sulfated polysaccharide from H. heliophila to the culture media produces significantly smaller aggregation. Similarly, the cell aggregates area was also reduced by the addition of Heparin, but only the higher concentration tested (10 mg/ml) showed significantly lower aggregates than the control. In order to further investigate the affinity between the sulfated polysaccharide of H. heliophila and Heparin we employed an affinity chromatography (HITRAP Heparin), that shows that the H. heliophila sulfated polysaccharide interacts with Heparin. Overall, these results indicate that both the homologous sulfated polysaccharide and heparin are able to avoid the sponge cell aggregation. The incapacity of heterologous sulfated polysaccharides to avoid the sponge cell aggregation confirms the species specific interactions between sponge sulfated polysaccharides. Financial support: CNPq and FAPERJ