The reproductive behavior of fresh water Anostracan has not been massively studied by the carcinology specialized literature, regarding especially the Dendrocephalus brasiliensis Pesta, 1921, about which there are abundant studies only on the geographical distribution of that Anostracan. The objective of this research was to investigate the reproductive behavior of this Anostracan in different periods (dry and rainy). For this, mature individuals of both sexes were used. They were collected in four ponds of the Fish Farming Station of Paulo Afonso (FFSPA), by monthly capture in each pond, within the period from December 2004 to November 2005. The reproduction type was observed by placing some females in aquariums with males and placing the other ones individually, starting from the nauplii phase, where they stayed for 15 days (reproductive age). The individuals' sexual proportion was calculated by the relative frequencies of males and of females, every month, for the whole collection period. At 10 days cysts production is possible and the number of produced cysts is related to the size of the female. The ratio male:female in the studied period was of 1 male to 1.07 female. The proportion male:female was 51.75% female to 48.25% male along the year. The observation of the reproductive behavior showed the reproduction is sexed.