This study is concerned with the numerical analysis of particulate jet generated by solid particles falling from a slit orifice into an unbounded quiescent air. A two-dimensional vortex method, proposed for the simulation of particle-laden free turbulent flow in prior papers, is employed for the analysis. The falling particles induce complicated air jet involving large-scale eddies around the jet. The air takes its maximum velocity at the center line of the jet. The effect of the particle diameter on the velocity distributions of the air is investigated. The entrained air flow rate is favorably compared with the value predicted by an analytical model.