A composition for controlling harmful bio-organisms comprising (a)at least one imidazole compound represented by formula (I)(see formula I)wherein R represents a lower alkyl group or a lower alkoxy group； and nrepresents an integer of 1 to 5, as an active ingredient, and (b) atleast one inorganic phosphorus compound as an active ingredient, and amethod for controlling harmful bio-organisms comprising applying thecomposition for controlling harmful bio-organisms onto harmful bio-organisms.
