This study was carried out from May 1995 to April 1996 in two streams within in the Adolfo Ducke Forest Reserve, located in Central Amazonia of Brazil. A total of 216 substrate samples was taken along 2000 m of each stream, starting from their origins, with the objective being to describe changes in structure of the Odonata community as a function of distance to the origin of the stream, substrate type, and season. Larvae of 24 species were identified. Cluster Analysis revealed two groups of associated species based on substrate type, and there was evidence of seasonal and spatial patterns in the abundance and diversity of these members. These patterns were most marked in substrate occupation. © 2002, Copyright Taylor & Francis Group, LLC.