To investigate the effect of large patch infection on oxidative stress induction, growth, $H_2O_2$ concentration and lipid peroxidation were compared between pathogen-infected and healthy (control) zoysiagrass. The sampling for leaves and roots were carried out every 2 days for a period of 6 days. Pathogen-infection increased root mortality by 30% compared to control. Dry mass was not significantly affected by pathogen-infection until day 4, but significant decreases in both leaves (-14%) and roots (-20%) were observed at day 6. The $H_2O_2$ concentration in pathogen-infected leaves rapidly increased within the first 2 days(+28%) and then slightly decreased. The increase of $H_2O_2$ in pathogen-infected roots was distinct, showing 1.7-fold higher level than control at day 6. The extent of lipid peroxidation caused by pathogen-infection continuously increased for the first 4 days. This was then stagnated until day 6. In roots, the significant increase of lipid peroxidation was observed only at day 2. These results indicate that large patch-infection induces oxidative stress, and that the oxidative stress responsive pattern was plant organ specific.