Abstract: The κ-ε turbulence model is used to establish a mathematical model of a plane negatively buoy ant inclined jet in static environment.Through the comparison of the calculated result and tested data of D.M.Shahrabani,predictions of these kinds of jets are made.The region of this flow can be divided into three parts,namely,jets region,recirculation region and horizontal spreading region.The demarcations between jets,horizontal spreading region,and the inner demarcation of jets region are given also.The position of the contracted section and the variations of velocity,density and turbulent kinetic energy along the contracted section are given in the end,which can be used as the boundary condition for calculation of far-field-behavior.