Authers Investigated the particulate size distribution in work environment of Banwol and Changwon industry complex. Size distributions of particles exposured to workers in welding and in grounding process were evaluated by personal cascade impactors. Personal air samplers with personal cascade impactor were attached to the workers. The mass median diameter measured in welding sites were 0.3 to 3.8μm and in grinding sites were 1.5 to 2.6μm. Respirable matter fractions were ranged 32.67 to 65.05%. Respirable matter fractions were calculated from the size distribution data by the respirable particle mass of the ACGIH criteria. The study relating to characteristics of particle of other industries and particulate size distribution is more needed in the near future.