In this study CALPUFF modeling was performed to predict a contribution of a separate single point pollutant source as well as of total point pollutant sources of major synthetic fiber manufacturers in Gumi national industrial complex to atmospheric trimethylamine concentration of the same area. In addition, a contribution of the separate single point pollution source to the atmospheric trimethylamine concentration of the same area was estimated relatively to the total point pollutant sources. As a result of the CALPUFF modeling, the maximum atmospheric concentration of trimethylamine in Gumi national industrial complex was appeared upon improving T company emission facility frequently in complex 3 in winter (January) and spring (April) while frequently in complex 1 in summer (July) and autumn (October). Besides, the predicted range of the maximum atmospheric concentration of trimethylamine in complex 1 was improved upon improving its emission facility. However, even though in complex 3 the upper bound of the predicted maximum atmospheric concentrations of trimethylamine was increased upon improving T company emission facility, the predicted value of their second upper bound below the upper bound was very similar to the upper bound of measured atmospheric trimethylamine concentrations in Gumi prior to improving its emission facility. Thus, the effect of improving T company emission facility was estimated huge in complex 1 while it was trivial in complex 3. These maximum concentrations of trimethylamine predicted to estimate the expected contribution of total point pollutant sources by CALPUFF modeling showed the similar values to those measured in the region of Gumi. Therefore, the expected contribution of total point pollutant sources to atmospheric trimethylamine concentration in the area of Gumi was validated.