Considering the importance of rainbow trout as a food fish, increasing the reproduction efficiency is necessary, by evaluating the gamete quality and fertilization ability. Production of all-female populations can have economic benefits in the rainbow trout industry. To produce all-female populations, larvae that have not yet fish that are genotypically XX or female to be created testis. The aim of this undergone sexual differentiation are first exposed to androgen, which causes examining sperm motility indices by the Computer-assisted sperm analysis (CASA). study was to evaluate the semen qualitative analysis of sex-reversed males by Including percentage of motile sperm (MOT), Velocity of Straight Line (VSL), Motility duration, sperm density and some semen biochemical characteristics such Velocity of Curved Line (VCL), Linearity (LIN) and Lateral Amplittude (ALH). a glucose, fructose, protein, Ca 2+ , Mg 2+ , Cl - , Na + and K + as well as pH were compared. The motility characteristics evaluated by CASA and motility durations in normal fish were significantly higher than sex-reversed males (p normal males (p 0.05). In comparison between semen biochemical indicies 0.05). The sperm densities of neomale fish were significanty higher than of K + , Na + , fructose and protein were between normal and neomale fish, it could be concluded that semen plasma levels significantly higher in neomale fish (p 0.05). The results of this study that the motility indicies of neomale fish were significantly lower than normal male. Such these differences, could be caused by differences in semen biochemical indices such as K + and Na + as well as fructose and protein between normal and neomale fish. Keywords : Rainbow trout, Oncorhynchus mykiss , CASA, motility, semen.