A compact and commercial aerosol generator capable of generating narrowly size-distributed aerosols with high mass concentrations was designed, fabricated and tested. The aerosol generator, consisting of a Delavan simplex nozzle (Model 30610-4), an L-shaped settling chamber and a virtual impactor with a clean air core. was modified and improved from Chein and Lundgren＇s work [20] to be more compact and readily commercial. The performance of the aerosol generator was evaluated using corn-oil, sodium chloride and uranine solutions. The results indicated that the corn-oil droplets produced by the generator had a mass medium aerodynamic diameter (MMAD) of 7.20+/-0.32 mu m with a geometric standard deviation (GSD) of 1.48 +/- 0.01 and the aerosol generation rate was 13.8 +/- 1.3 mg/min. Solid aerosols generated from NaCl solution were found to have an MMAD in the range 1.39-4.88 mu m with a GSD of 1.34-1.47 with the volumetric solution concentration varying from 0.1% to 9%. At the same time, the aerosol generation rate varied from 0.27 +/- 0.05 to 15.8 +/- 1.8 mg/ min, depending on the solution concentration and the particle size produced. In addition a 0.01% uraniane solution was tested to generate a submicron aerosol with an MMAD of 0.93 mu m and a GSD of 1.48.