Abstract: This work uses a technique for injecting high amplitude and low mass flux pulsed slot jets into subsonic shear layers for the purpose of jet mixing enhancement. The 3-D flow fields of the jets with pulsed jet blowing for mixing enhancement were simulated numerically. The finite volume method, RNG k-ε turbulence model were employed to solve N-S equation. Numerical simulations of low Mach number 0.2 and middle Mach number 0.6 jets exhausting into fluid were conducted. These simulations show that pulsed jet blowing effected on either low Mach number jets or middle Mach number jets causes the jet to expand rapidly in the plane parallel with the actuators and to contract in the plane perpendicular to the actuators, the intensity of motion and associated mixing are higher when the excitation Strouhal number is around 0.2, and small injection flow rates can provide tremendous increases in both velocity and temperature decay rates. With the increase of the pulsed slot jet mass flux, a better mixing can be obtained.