The foraging efficiency of Great Egrets (Ardea alba modesta) in two different habitats (rice fields and reservoir habitats in Asan City, Chungcheongnam-do, Korea) was compared during the breeding seasons (May to June) of 2006 and 2007. The feeding activities of Great Egrets in both rice fields and reservoir habitats showed similar seasonal patterns. Pecking and capture rates were higher in June than in May, but the prey items captured were larger in May than in June. The feeding activities of Great Egrets also showed significant variation among microhabitat types within a reservoir. For instance, pecking and capture rates were higher in areas with submerged plants, but the capture success rate did not vary according to microhabitat type. In the rice field habitats, Great Egrets had higher pecking rates in the planting stage than in earlier stages (i.e., flooding and plowing stages), and they also walked more to find prey. These results indicate that the feeding efficiency of Great Egrets varies according to the structure and condition of their feeding habitats. However, the feeding activities of Great Egrets were similar between rice fields and reservoir habitats. Therefore, the results of this study suggest that during the breeding season, both rice fields and reservoirs may provide important feeding habitats for Great Egrets.