The present study aims to determine the effect of different concentrations of EDTA (0 g EDTA/L, 0.1 g EDTA/L and 0.3 g EDTA/L) on fecundity, survival rate and biochemical responses of the adult female of Nile tilapia, Oreochromis niloticus
reared in glass tanks. Results showed that, the fecundity increases with the increasing in the concentrations of EDTA compared with control. Survival rate are affected by high concentration of EDTA (0.3 g EDTA/L) and reached to 33.3 % at the end of third week. However, an addition of EDTA to aquaria containing adult females increased the biochemical parameters at high concentration compared with control and low concentration samples except total proteins showed deceasing to lowest level. Statistical analysis mentioned a significant difference between the low concentration
of EDTA and both of high concentration and control in all parameters. Otherwise, total carbohydrates exhibit non significant differences between all of them.