Ferrites like ZnFe2O4 and NiFe2O4 are heated in-situ in XPS chamber upto 300°C. It has been observed from XPS that ZnFe2O4 undergoes surface enrichment of Fe after 250°C whereas NiFe2O4 does not show such changes. The minute chemical changes are interpreted from the changes in Fe2p and Ni2p peaks due to heating.