A numerical investigation has been carried out to study the influence of nozzle geometry on the mixing characteristics and turbulent behaviors in turbulent jets. The geometry investigated was ellipse lip shape with aspect ratio of 6 and 10. By substituting an equivalent area rectangular jet a large aspect ratio rectangular jet (AR=6 and 10), the elliptical jet in uniform flow was computationally modeled using the realizablek-ε model parameters. The numerical calculation focused on time-average centerline concentration dilution of elliptical jet at the same momentum flux (Me =5.〖10〗^4) under a jet to ambient velocity ratio (R’=45) and a very high Reynolds number to ensure the turbulent condition in order to compare the numerical model with the experimental data. The model has been rigorously validated by a series of basic experiments designed to give concentration data that allows an accurate determination of the jet properties. We found out that there was no discernible difference between the two centerline dilutions of the two different aspect ratios. The examination of the cross-sectional images indicates that the spreading rate in the major and minor axis planes is totally different, the cross-sectional shape of the elliptical jet kept changing with time, large spreading is observed in the minor axis plane than that in the major-axis plane, and this causes the jet to gradually decay from its initial shape to the ultimate rounded one. Furthermore, the effect of the axis switching of elliptical jet can be clearly observed at the distance cross-section x =4D to 13.3D. The calculated results reported that the spreading and decay rate of the elliptic nozzles are higher than results for round jets. The jets issuing from the elliptic nozzle have great mixing of the surrounding fluid.