The Amazon has a great biodiversity, however in this regions some locations still without no research, showing the need for studies in this localities. The lack of information about the diversity of frogs and the speed of change in the landscape that have been taking place on the planet, demonstrates the urgent need to preserve the remaining resources. In this adverse scenario, live frogs that are sensitive to changes in natural forest areas, and are recognized as Bioindicator of environmental integrity. The present study had scoped to do a survey of the anuran species in a country area, near to the city of Porto Velho (RO). This land, is formed by two separate areas, one classified as secondary forests and the other as pasture area. The sampling was carried out from January to may 2012, using tools and techniques for catch in the night delimited by time, pitfall traps and frogs occasional meetings Were captured 63 specimens of Anurans, distributed in six families, where the richest in species were the Leptodactylidae (n = 6), Hylidae (n = 5), Bufonidae (n = 4), Microhylidae (n = 2), Brachycephalidae (n = 2) and Aromobatidae (n = 2), totaling 21 species identified.The most abundant species were the Leptodactylus chaquensis (n = 12) and Leptodactylus andreae (n = 8). The pasture area exhibited the greatest number of individuals captured with 65.07% of all frogs collected
