The firing temperature dependence has been studied of the quadrupole splitting (QS)and isomeric shift (IS) for the structure iron in Yuan dynasty Jun porcelain glaze and simulated ancient blue Jun glaze by Mossbauer spectroscopy. The QS and IS for the two kinds of glaze were compared. Firing temperature for the former was determined to be above 1250℃
and coordination number for Fe2+ and Fe3+ was four. The latter has been found will a broad process of dehydroxylation and vitrification
which may be profitable to form the unique glaze colour of Jun porcelain. When firing temperature is above 1200℃