We discuss the effects of galactic spiral arms on the alpha-coefficien
t, turbulent diffusivity and turbulent energy density of the interstel
lar turbulence. We argue that the alpha-coefficient and the dynamo num
ber are larger in the interarm regions, whereas the kinetic energy den
sity of turbulence is larger in the arms; the turbulent magnetic diffu
sivity can be only weakly affected by the spiral pattern.