  We investigated the possible feedback of type-I burst to the accretion
process during the spectral evolution of the atoll source 4U 1608--52. By
fitting the burst spectrum with a blackbody and an adjustable, persistent
spectral component, we found that the latter is significant state-dependent. In
the banana state the persistent flux increases along the burst evolution, while
in the island state this trend holds only when the bursts are less luminous and
starts to reverse at higher burst luminosities. We speculate that, by taking
into account both the Poynting-Robertson drag and radiation pressure, these
phenomena may arise from the interactions between the radiation field of the
type-I burst and the inner region of the accretion disc.
