Preliminary results of the creation of the Pulkovo electron database of sunspot magnetic fields are presented. The database includes observations at seven observatories in the scope of the National Program of Solar Service for 40 years. In different periods of time, Crimea Astrophysical Observatory, Main Astronomical Observatory, Siberian Institute of the Terrestrial Magnetism and Radio wave Propagation (Irkutsk), Institute of Terrestrial Magnetism and Radio wave Propagation (Troitsk, Moscow Region), Shamakha Astrophysical Observatory, Observatory of the Ural State University, and Ussuriisk Astronomical Station participated in these observations; however, only two first observatories from this list conducted continuous observations in 1957--1997. A series of a new activity index, annual mean values of the magnitudes of sunspot magnetic fields in the Pulkovo system, is presented.