  The shapes of pulse profiles, especially their variations with respect to
observing frequencies, are very important to understand emission mechanisms of
pulsars, while no previous attempt has been made in interpreting the
complicated phenomenology. In this paper, we present theoretical simulations
for the integrated pulse profiles and their frequency evolution within the
framework of the inverse Compton scattering (ICS) model proposed by Qiao (1988)
and Qiao & Lin (1998). Using the phase positions of the pulse components
predicted by the ``beam-frequency figure'' of the ICS model, we present
Gaussian fits to the multi-frequency pulse profiles for some pulsars. It is
shown that the model can reproduce various types of the frequency evolution
behaviors of pulse profiles observed.
