Abstract
We present results of the analysis of NOAA 8668, which was observed successively by space satellite (SOHO) and ground-based observatories (BBSO, Huairou). The combined observation offers us a good example of a region observed from low to high solar atmosphere. Several flares and a sigmoid filament were observed in the AR, and we observed the sigmoid filament from its birth to disintegration. The configuration of the magnetic field of the AR changed quickly as well as the loops. From EIT movies, we can even judge the sign of the sigmoid filament's magnetic helicity. The forming and heating of the loops were the result of magnetic reconnection, and the corona seemed heated when the loops became opened.