Flame atomic absorption spectrometry (FAAS) was applied to determine the content of heavy metal ions of packaging paperboards of nine producers. The causes of higher heavy metal ions content was analyzed by energy dispersive spectrometer analysis and microscope observation. The result showed that only paperboards from two producers do not detect heavy metal ions; paperboards from the other seven producers differently contain heavy metals ions, in which product of two producers have heavy metal ions content beyond the top limit of European Union standards. Papermaking raw material itself and the additives are the main causes of higher heavy metal ions content. The process requirements in papermaking was put forward to control the heavy metal ions content.