Composition for controlling harmful bio-organisms and method for controlling harmful bio-organisms using the same

A composition for controlling harmful bio-organisms, which composition has curative and/or preventive synergistic effects on plant diseases, and is useful in agriculture and horticulture, comprising

• (a) at least one imidazole compound represented by formula (I):
• wherein R represents a lower alkyl group or a lower alkoxy group;
• and
• n represents an integer of 1 to 5, as an active ingredient, and
• (b) at least one inorganic phosphorus compound as an active ingredients wherein the imidazole compound and the inorganic phosphorous compound are at a weight ratio of 1:300 to 300:1, wherein the respective amounts of the at least one imidazole compound (a) and the at least inorganic phosphorus compound (b) can be reduced or the respective control spectra broadened as compared with the individual use of the at least one imidazole compound (a) or the at least one inorganic phosphorus compound (b).