In this study, the distribution characteristics of nano-TiO2 aerosol have been studied to get insight of the suspension, agglomeration and depositing performances of aerosol nanoparticles in the workplace. The number concentration and mass concentration of the aerosols have been characterized by using a wide-range particle spectrometer and cascade impactor samplers, respectively. Water based wet aerosol samplers, as well as its corresponding analysis approaches based on ultraviolet spectrometry, have also been developed to investigate the mass concentration and present an efficient sampling performance with the quite shorter sampling time than that by cascade impactors. To get a comparison of the test results with each other, sampling points have been set at the heights of breathing zone (1.0, 1.5 and 2.0 m) and at the distances of 1 to 5 m away from the discharge port of the assembly line. It is found that all the number concentration curves exhibit two peaks at the ranges of 10–200 nm and 500–900 nm. The aerosol particles with distance of 3 m exhibit the highest number concentration at all the diameter range except for the diameter less than 20 nm. While, aerosol at the distance of 5 m presents the highest number concentration, up to 18000 particles per cm3, in the diameter less than 20 nm. It is attributed to the spray forces of the discharge port and the suspending and depositing of aerosol nanoparticles in the air. The mass concentration and particle weight percentage at different diameter tested by cascade impactor show a strong dependence on the number concentration, which is well consistent with the results obtained by wet method.