Mangiferin (1,3,6,7-tetrahydroxy xanthone-C2-b- D-glucoside) promoted vegetative growth and exhibited inhibitory role on the occurrence of malformation. Mangiferin changes associated with mango malformation pathogens were fol-lowed after inoculated mango seedlings (three years) with malformation pathogens i.e. Fusa-rium subglutinans, F. sterilihyphosum, F. ox-ysporum and F. proliferatum. Mangiferin re-mained at lower level in leaves of malformed shoots as compared to healthy one. The floral malformation was observed to be associated with the reduction of mangiferin. Strong positive correlations between mangiferin activity and malformation incidence were observed. Mangiferin level at panicle initiation may give a possible estimate of malformation incidence in mango. Keywords: Fusarium; Mangiferin; Mango Malformation