This work is devoted to the new phenomena appearing in radio emission in preflare active regions that were found with the use of radio telescope RATAN-600. The first is the complicated spectral-polarization behavior in narrow frequency range and, in particularly, the double changing of the polarization emission sign in active region at the time interval of several days before big flare. The second, the detection of regular decreasing of radio brightness radio darkening of active regions, which is also observed in a few days prior to flare [Tokhchukova & Bogod (2003)].To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html