To obtain a composition for improving a plant or a soil, having a stable growth promoting function for the plant, improving a pathological resistance of the plant itself, showing antagonistic action on phyto-pathogenic fungi and further promoting the formation of a polyuronide by microorganisms for the soil and showing a buffer capacity to the soil, and to provide a method for using the composition.

This composition contains (Element A group) at least one substance selected from the group consisting of Iou stone, granite porphyry silicic acid, iron, zinc, copper, molybdenum, magnetite, tourmaline, manganese, iodine and boron, (Element B group) at least one substance selected from substances having a bactericidal action and a bacteriostatic action such as biopreservatives obtained from a lactic acid fermentation and produced by a lactic acid bacillus, (Element C group) at least one substance selected from an albino protein extract, Stevia rebaudiana, preferably, the composition contains at least one substance selected from each of groups as above, calcium biphosphate (monobasic), the biopreservative and Stevia rebaudiana produced by a lactic acid bacillus.