To provide an organic titanium oligomer stable to hydrolysis and keeping the catalytic activity and a method for producing the oligomer and to provide an eco-friendly method for producing an organic titanium oligomer.

The organic titanium oligomer is expressed by formula (1) (in the formula, R1, R2, R3 and R4 are each independently a 1-12C alkyl group or alkenyl group which may have a substituent; and n is a real number of 2). The method for producing the organic titanium oligomer comprises the addition of water or a mixture of water and a water-soluble solvent to a tetraalkoxytitanium essentially without diluting the compound with a solvent and the hydrolysis of the compound.