A monitoring system for atmospheric CFC-12 and CFC-11 has been established at Mt. Kwan-Ak, Seoul National University (SNU) since July, 1991. The concentrations showed quite a large variation ranging from 495 to 37600 pptv (pptv=part per trillion, 10$^{-12}$ , v/v) for CFC-12 and from 233 to 12100 pptv for CFC-11 due to many local sources. However, monthly medians show rather limited ranges ; 553~765 pptv for CFC-12 and 301~431 pptv for CFC-11. Furthermore minimum concentrations could be defined relatively well during the whole period of observation. The regional background concentrations in 1993 near SNU wer estimated as 533 pptv for CFC-12 and 293 pptv for CFC-11. These values are very comparable to global averages in Northern Hemisphere, 523 pptv for CFC-12 and 287 pptv for CFC-11, reflecting the fast atmospheric mixing processes within the hemisphere. Examinations with meteorological parameters such as wind speed and direction suggest the possible measurement-window at SNU, appropriate for regional monitoring. Studies for improving the monitoring capability of the SNU station such as automation of the analysis system along with correlation with other meteorological parameters, are in progress at the present time.