It is to provide a solution for forming an organic metal thin film that can form rapidly a dense monomolecular film with less impurity. A solution for forming an organic thin film comprising (A) at least one organic metal compound shown by the following formula (I) (provided that at least one organic metal compound contains a hydroxyl group); and (B) at least one organic metal compound shown by the following formula (II), R3mM2X54-m  (II) wherein the solution is 40≦[(A)/{(A)+(B)}]×100≦100 (mass %), and 0≦[(B)/{(A)+(B)}]×100≦60 (mass %); or a solution for forming an organic thin film comprising an organic metal compound having at least one hydroxyl group and at least one hydrolysable group among the organic metal compounds shown by the following formula (I); or a solution for forming an organic thin film wherein the mass ratio of trimer with respect to dimer is greater than 0.5 among the metal organic compound shown by formula (I).