A method of production of modified conjugated diene-based rubber comprising a steps of using, as a polymerization initiator, an alkali metalated aromatic compound which has three or more carbon atoms which are directly bonded to alkali metal atoms and aromatic rings in one molecule so as to polymerize a monomer which contains at least a conjugated diene compound and reacting a compound of the following general formula (I) with an active ends of the obtained polymer is provided. (In the general formula (I), any one of R1 and R10 to R18 is an atom or reactive group which can react with the active ends of said polymer or a hydrocarbon group which includes either of the same, the remaining among R1 and R10 to R18 and R2 to R9 are respectively independently a hydrogen atom, alkyl group, or aryl group, and “j”, “k”, “m”, and “n” are integers of 0 to 100.)