This study was carried out in three tropical rivers, namely Humadea (488m. above sea level), Marayal (503m. asl) and Camoa (450m. asl), located in the foothill on the Eastern Plains of Colombia, with average temperature as high as 24ºC, and 4000mm average annual precipitation. The samplings were carried in rainy seasons during 2003 to 2007 to date. During the field survey stage, hydro physicochemical indices were obtained and analyzed, and the Acuatic Macroinvertebrates Epicontinental (AME) were captured. Based on laboratory survey and sampling work Shannon- Weaver (H’), Sorensen (s) and BMWP (Biological Monitoring Working Party Score System)(2007) adapted to Colombia. During the study period, not recorded naturally or by human intervention strong or severe disturbance of ecological status of these three ecosystems that alter their structure and dynamics, aspects to date (July 2014) of preparation of this article remain unchanged. 56 Genera, 40 families, 13 Orders, four Classes and three Phyla were recorded. The highest value for diversity according to the Shannon Weaver index was found in the river Marayal (2.72), while the lowest diversity was found in the Humadea river (2.53). On the BMWP index the three systems present water quality levels ranging between good and very good. The ecosystems registering the highest similarity were Marayal and Camoa (81%) while Humadea and Camoa had the lowest (56%).