DIFFERENTIAL DISTRIBUTION OF PALYNOMORPHS IN THE GUANABARA BAY, RIO DE JANEIRO, BRAZIL. The present paper aims to characterize the modern depositional processes that control the palynomorph accumulation in several sectors of the Guanabara Bay. A total of 27 samples of surface sediments obtained inside the Guanabara Bay were collected and treated using palynological sieving methodology followed by the standard chemical treatment for Quarternary sediments. The results obtained showed a high percentual of fields (“Vegetacao Campestre”) elements and a high richness of pollen grains from the mixed rainforest (“Floresta Ombrofila” ). The differential distribution of palynomorphs followed a pattern that was influentiated by the bathymetry associated to the guidance of tide currents, which originated the highest concentration of palynomorphs in the deeper and topographical obstructed areas. The differential deposition in relation to the size of palynomorphs followed a model of accumulation of small palynomorphs inside the areas of high energy of the aquatic flow, and large size palynomorphs in quiet water areas and laterally to the discharge of the rivers.