PURPOSE: To easily obtain a complex useful as an organic electroluminescent agent excellent in luminance and luminescence stability, by reaction between an anhydrous aluminum halide and 10-hydroxy[H]quinoline in an organic solvent to produce a complex which is then separated and purified on sublimation.

CONSTITUTION: A complex is first obtained by reaction between (A) an anhydrous aluminum halide such as anhydrous aluminum chloride and (B) 10- hydroxy[H]quinoline in (C) an organic solvent soluble for both the components A and B (e.g. an alcohol, ether, ketone), and this complex is separated from the system, being sublimated under a vacuum and purified to obtain the objective 10-hydroxybenzo[H]quinoline-aluminum complex.