During the months of December 2008 to February 2009 were conducted six biweekly sampling to characterize fitoperifiticas community and aquatic macroinvertebrates in a stretch of river pacurita, through the identification of families and genera (algae and aquatic macroinvertebrates), and their influence on some physical, chemical, aquatic macroinvertebrates were collected algae and periphyton of microhabitats present, fast-flowing stone (PR), slow-flowing stone (PL), litter (H), trunk (T ) and riverine vegetation (VR) as well as some variables were measured climatic, physical and chemical properties of water as precipitation, electrical conductivity, water temperature, total solids, pH and dissolved oxygen, is a high number of organisms representing a total of fitoperifiticos 301 individuals divided into 4 divisions, 4 classes, 10 orders, 16 families and 28 genera, and for the community of macroinvertebrates were recorded 128 specimens, which were grouped in a class, 8 orders, 18 families and 27 genera; as alos microhabitats, there was no statistically significant difference for periphytic algal community or in the case of aquatic macroinvertebrates.