The family Cactaceae Juss. is distributed throughout the Brazilian territory, represented by 39 genus and 261 species. In Northeastern Brazil, these are species of great economic interest and used for various purposes, such as forage, human food, medicinal and ornamental use, in addition to being important in maintaining regional biodiversity. Flora studies gather information that describes the diversity, use and conservation of plant species in a specific region, and include identification keys traditionally in the dichotomous format. Interactive electronic keys are more recent tools that associated to floras contribute substantially to the popularization of taxonomy and to the advancement of floristic, systematic and conservation studies. In this work, we aim to present a flora of species of Cactaceae and an interactive identification key for species that occur in Rio Grande do Norte, Brazil, listing their distribution, information on conservation data and description of species in the state. The construction of the key was in the free access software Xper² and, further on, the database was exported to the Xper³ platform and made available online. From data collection in the field and herbaria data, it was possible to document and describe 9 genera and 18 species: Brasiliopuntia (1), Cereus (2), Melocactus (3), Nopalea (1), Opuntia (2), Pereskia (1), Pilosocereus (4), Rhipsalis (1) and Tacinga (3). Data on geographic distribution, phenology, and ecology and conservation about the species were also presented.