We summarize our previous results concerning the local magnetic field formation, showing that its sunspot groups developing to reach higher typec C, D, E etc. continue their magnetic evolution during the period of new magnetic flux addition immediately
after the first magnetically bipolar balanced stage. It is probably a magnetohydrodynamical process of magnetic field strenthening oř a new magnetic flux generation. It is dosely related to a specific singularity in the local magnetic field topology at the inner field boundary not far from the centre of the group, where the gulf of one polarity is compressed inbetween the boundary curvature of the
field of opposite polarity and where large radial velocities can be observed. This is the region, where new peaks of both the leading and the following polarities in a speciál orthogonal relation of the new to the old tubes of lines of force develop, where the greatest field gradiente are formed. The flare frequencies and their importances correlate well with the degree of complexity of magnetic field topology in this situation. The important role of the photosphere in all these processes is underlined.