Changes in total phospholipids and activities of two phosphoric diester hydrolases,i.e. phospholipase C and phospholipase D have been studied in inoculated wheat leaves of 25-day old plants, interacting differentially with three races of brown rust,Puccinia recondita, during early stages of pathogenesis. With progressive rust iafection the lipids and phospholipids were found to decrease in all the three interactions except at later stages (48 h and 72 h) in race 104-interaction. However, total phospholipids at various stages were found to be higher in resistant interaction (race 63) as compared to the other two interactions. An initial increase in activities of phospholipase C and D in all the three interactions was followed by a decline at the intermediate stages which continued in case of phospholipase C activity while a reverse trend was observed in phospholipase D activity towards later stages of infection. Further the enzymatic activities at various stages were found to be higher in the susceptible and intermediate interactions (with races 77 and 104 respectively) as compared to the resistant interaction.