  Based on a linearized model of the Yarkovsky effect, we investigate in this
paper the dependence of the semimajor axis drift $\Delta a$ of a celestial body
on its size, spinning obliquity, initial orbit and thermal parameters on its
surface. With appropriate simplification and approximation, we obtain the
analytical solutions to the perturbation equations for the motion of asteroids
influenced by the Yarkovsky effect, and they are then verified by numerical
simulations of the full equations of motion. These solutions present explicitly
the dependencies of $\Delta a$ on the thermal and dynamical parameters of the
asteroid. With these analytical formulae for $\Delta a$, we investigate the
combined seasonal and diurnal Yarkovsky effects. The critical points where the
migration direction reverses are calculated and the consequent selective
effects according to the size and rotation state of asteroids are discussed.
%Solely the Yarkovsky effect is found to be able to produce some ring structure
in the aged circumstellar debris disk. Finally, we apply the analytical
formulae to calculate the migration of Eos family members. The space
distribution of asteroids is well reproduced. Our calculations suggest that
statistically the orientations of spin axes of family members satisfy a
random-obliquity distribution, and the rotation rate $\omega_{\rm rot}$ of
asteroid depends on its size $R$ by $\omega_{\rm rot}\propto R^{-1}$.
