ABSTRACT The aim of this experiment is to reduce the intensity leaf spot desease (Cercospora ap.) attack an and increase the yield of groundnut (Arachis hypogaea L.) by the usage of right fungicide and the optimal plant spacing. The experiment was done fron June 22, 1990 up to Sep- tember 29, 1990 at Kedungsari Village, district of Morth Magelang, Nagelang municipality, Central Java Province,…