Method for producing indolylalkyl succinic acid amide compound

Disclosed is a novel method for producing an indolylalkyl succinic acid amide compound, which is useful as a plant growth accelerator, by microorganisms. Specifically disclosed is a method for producing an indolylalkyl succinic acid amide compound represented by general formula (2) (wherein R 1 , R 2 and n are as defined below) or a salt thereof, which is characterized in that microorganisms belonging to the genus Bacillus and having the power of synthesizing an indolylalkyl succinic acid amide are cultured in a medium containing an indolylalkyl amine represented by general formula (1) (wherein R 1 and R 2 each independently represents a hydrogen atom, a halogen atom, a hydroxy group, an alkoxy group or an alkyl group; R 3 represents a hydrogen atom or a carboxyl group; and n represents a number of 0-3) or a salt thereof.