The key points of pneumatic nebulizer are the area ratio of solution noz- zle to gas nozzle, concentricity and thin wall. Those factors effect the nebulize efficiency, sensitivity and precision directly. In this paper, the calculation me- thod of choosing diameters of tile two nozzles of nebulizer, techniques for making thin-wall capillary and sealing two nozzles concentriclly and other factors effecting the precision were described.