An investigation of the jet trajectories and mixing behaviour of venturi-jet mixers to mix incompressible fluids in which turbulent jet injects fluid at an arbitrary angle have been studied experimentally and numerically by writing conservation equations in natural coordinate system and also by using FLUENT CFD code. Numerical results of an incompressible cross flow-jet mixing in venturi-jet mixers are presented and validated against experimental results. The effect of jet injection angle, cross flow Reynolds number and velocity ratio on entrainment and mixing of jet with incompressible cross flow in venturi-jet mixer were analysed. Twenty five cases were studied, including 5 different initial injection angles 45o, 60o, 90o, 120o, 135o and 25 different jet momentum ratios to evaluate the entrainment of jet and mixing performances of the mixer.