The purpose of this study is to validate and verify a head nose exposure inhalation system for nano particle inhalation toxicity studies. Carbon nano tube(CNT) particles were generated by a chemical vapor deposition(CVD) generator. And purchased single wall carbon nanotubes(SWCNT) and multi wall carbon nanotubes(MWCNT) were generated by an atomizer. CNT particle distribution was measured by Scanning Nano-Particle Spectrometer(SNPS) and Condensation Particle Counter(CPC). Diameter and length of MWCNT generated by CVD were 10~40 nm and 220~20 μm respectively. Particle number concentration of MWCNT generated by CVD were 1.3×105, 4.1×104, 5.6×103#/cc in high, middle, low chamber respectively. Distribution of particles which were less than 100 nm was 45%. Particle number concentration of SWCNT generated by atomizer after magnetic stirring were 8.5×106, 5.3×105, 1.1×104#/cc and after sonication 6.7×106, 4.1×105, 9.5×103#/cc in high, middle, low chambers respectively. Particle number concentration of SWCNT generated by atomizer after magnetic stirring were 6.7×106, 4.6×105, 8.6×103#/cc and after sonication 7.7×106, 5.1×105, 1.3×104#/cc in high, middle, low chambers respectively. We set up head nose exposure inhalation system to conduct a study on nano particle inhalation toxicity. There were sufficient particle number concentrations of nano particles generated in each chamber. Keywords : Head nose exposure, CNT(carbon nano tube), Particle size distribution