Solar Physics Russian The transition condition from the tachocline to the solar convective zone with a change of diffusion coefficient is considered. The topology of the magnetic fields participating in the process of dynamo is revised. We accept that the fields with intermediate values (of the order of 10 mT) have a dominant role in generating new cycle fields. It is found that the use of meridional circulation results in the increase of dynamo-wave period comparable with observed one. This indicates that α and Ω-effects are unimportant in the calculation of solar cycle period but they are important for the determination of peak value.solar dynamo cycle