In this study we present the study of solar active regions based on BOAO vector magnetograms and Hα filtergrams. With the new calibration method we analyzed BOAO vector magnetograms taken from the SOFT observational system to compare with those of other observing systems. In this study it has been demonstrated that (1) our longitudinal magnetogram matches very well the corresponding Mitaka's magnetogram to the extent that the maximum correlation yields r=0.962 between our re-scaled longitudinal magnetogram and the Mitaka's magnetogram; (2) according to a comparison of our magnetograms of AR 8422 with those taken at Mitaka solar observatory their longitudinal fields are very similar to each other while transverse fields are a little different possibly due to large noise level; (3) main features seen by our longitudinal magnetograms of AR 8422 and AR 8419 and the corresponding Kitt Peak magnetograms are very similar to each other; (4) time series of our vector magnetograms and H-alpha observations of AR 8419 during its flaring (M3.1/1B) activity show that the filament eruption followed the sheared inversion line of the quadrupolar configuration of sunspots, indicating that the flare should be associated with the quadrupolar field configuration and its interaction with new filament eruption. Finally, it may be concluded that the Solar Flare Telescope at BOAO works normally and it is ready to do numerous observational and theoretical works associated with solar activities such as flares.

• YONG-JAE MOON(Bohyunsan Optical Astronomical Observatory, Korea Astronomy Observatory)
• YOUNG DEUK PARK(Bohyunsan Optical Astronomical Observatory, Korea Astronomy Observatory)
• HONG SIK YUN(Department of Astronomy, Seoul National University)
• EUN-AH CHO(Bohyunsan Optical Astronomical Observatory, Korea Astronomy Observatory/Department of Astronomy and Atmospheric Sciences, Kyungpook National University)