Linear absorptive properties of the periodic multi-quantum well (MQW) structures are studied. It is found that the absorption is determined by the interplay of pulse widths, layer number N and periods. A threshold existing in N divides Bragg absorption into a rising and dropping regions. The corresponding maximum is an independent constant. Absorptions for non-Bragg arrangement keeps monoton ously increasing with its first part almost coinciding with the corresponding Br agg absorptions.This demonstrates a dramatic Bragg suppression,which never appea rs in the rising region. Further more, the Beer's law is proved to be still exac tly suitable for periodic structures.