Structure variations in the plasma and dust tails of the comet C/2006 M4 (SWAN) are studied for a long period of observations, namely, from September to December 2006. The dimensions of grains emitted by the comet for all interval of the observations are obtained from the dynamical analysis of images of the comet. On the basis of calculation results for aberration angle of the cometary plasma tail, the radial component of solar wind velocity at high heliographic latitudes are derived. Fast changes in the calculated values of solar wind velocity are caused by its variable transversal component.