FIELD: organic chemistry, fungicides, agriculture. SUBSTANCE: invention describes the novel fungicide synergistic composition comprising (4-S)-4-methyl-2-methylthio-4-phenyl-1-phenylamino-2-imidazoline-5- one of the formula (I) 
and compound (II) taken among the group including the compound (IIA), i. e. propamocarb-3-(dimethylamino)propylcarbamate; compound (IIB) 
, i. e. 1,2,3-benzothiadiazole-7-thiocarboxylic acid S-methyl ester; compound (IIC), i. e. ciprodinyl-2-phenylamino-4-cyclopropyl-6- methylpyrimidine; compound (IID), i. e. 2-hydroxybenzoic acid or salicylic acid and its salts; compound (IIF), i. e. spiroxamine-8-tert.-butyl-2-(N-ethyl-N-n-propylamino)-methyl-1,4-dioxaspiro[4,5] -decane; compound (IIG), i. e. [2-methyl-1-(1-p-tolylethylcarbamoyl)-propylcarbamic] acid iprovalicarbisopropyl ester taken in the ratio of compound (I)/compound (II) in the range 0.01-10. Invention describes also method for prophylaxis and treatment of crops against phytopathogenic fungi by application of the effective and non-phytotoxic dose of fungicide composition on plants. Invention provides the improvement of spectrum of activity and possibility for decrease of corresponding dose of each of active substances used. EFFECT: improved method of prophylaxis and treatment, valuable agricultural properties of compounds. 19 cl, 9 dwg, 2 tbl
