The present invention provides a fungicide composition having stable and high harmful bio-organism control effect on crop plants infected with plant diseases due to plant diseases. Specifically, the present invention provides a fungicide composition for agricultural or horticultural use, which comprises: (a) an indole compound represented by formula (I): wherein R 1 and R 2 each independently represents C 1-4 alkyl, etc.; Y represents H, halogen, etc .; R 3 and R 4 each independently represents a hydrogen atom, alkyl, etc .; R 5 , R 6 , R 7 and R 8 each independently represents a hydrogen atom, alkyl, etc ., and (b) at least other fungicide selected from the group consisting of Dimethomorph, Chlorothalonil, a copper compound, Iprovalicarb, Zoxamide, phosphorous acid or a salt thereof, Fluazinam, Cyazofamid, Flumorph, Benthiavalicarb-isopropyl, Ethaboxam, Methalaxyl-M and Benalaxyl-M.