Six sampling points were selected from an area adjacent to the Barro Colorado Island during a seven months period (january-july 1998) for the object of our study to know its physical-chemical and biological parameters with respect of the influence of the dry and rainy season. Statistical analyses of the samples were performed to determine the possible existing relationship of abundance and macrobenthic biomass in relation to the total organic carbon (TOC) in sediments, dissolved oxygen (DO) and sediments profile. Like wise, data analyses of the relationship of plankton and physical-chemical parameters (temperature, DO, phosphates and turbidity) were measured. During the period of research, it was noticed that environmental parameters showed variations with very slight significant changes for all stations. Moreover, an increase of phosphates and TOC’s been apparent during the rainy season. Granulometric analyses showed a greater percentage for sand, silt and clay at stations E-1, E-4 and E-5. Benthos community structure profile for both sectors (A and B), presented monthly and stationary variations of abundance and biomass; and also were significantly correlated in some cases with TOC’S and DO. During study period, the mayor abundance and biomass were those for station E-1. Plankton dynamics for both sectors studied were distributed discretely, and presented differences in their community composition for the seven months through out all stations. Phytoplankton community densities were high during the month of april. Zooplankton densities were abundant during the month of march. Correlation analyses of plankton community with respect to environmental parameters were marginally significant through out the period of research.