The purpose of the present study is to monitor diverse herbivore’s feeding activity in two localities, Mt. Jirisan National Park, a Korea LTER site and Mt. Seungdalsan, Muan, Jeonnam. We selected 11 tree species at two localities by differing elevations (> 200, 300, 600, 900, 1200m). We measured the herbivore’s feeding activity by an indirect method that calculates feeding area per leaf by diverse but unknown herbivores (ankertrass area) every two weeks from April to July. We found that the peak and duration differ along the elevation and locality: at a low elevation site (>300m), pattern of ankertrass area increased continuously from 16th Julian week to 21st week; at middle elevation site (600m), pattern of ankertrass area increased continuously from 20th Julian week to 23rd week; and at high elevation site (>600m), pattern of ankertrass area sharply increased from 22nd Julian week to 25th week. This showed that the timing of peak of herbivore activity exhibited a time-lag by elevations. We expected that the peak or duration of herbivore activity can be changed followed by environmental change and this can be monitored in a long term ecological monitoring.