In this paper, following the method used in [1-3], we present a quantum treatment of optical selforganization of a system of excitons and biexcitons. The cavity is subject to the action of external coherent field. It is assumed that the exciton, biexciton and photon modes are damped due to the interaction with the reservuar. We consider the phenomenon of optical self-organization in the simplest geometry of a ring cavity with high Q - factor. The photons of the propagating pulse excite biexcitons from the ground state of the crystal as a result of the two-photon absorption process. The Hamiltonian of the problem consists of a sum of Hamiltonians of free excitons, photons and biexcitons - HF, the Hamiltonian describing the interaction of the external field of amplitude E and frequency ω0 - HE, the Hamiltonian of photon, exciton and biexciton interaction - HI, and the Hamiltonian of interaction of photon, exciton and biexciton with a thermostat - HD F E I D H = H + H + H + H , (1) where H a a b b c c F = ω + + ω + + ω + 1 2 , ( i 0t i 0t ) E H = i Ec+e− ω − E∗ce ω , ( ) ( ) I H = −g c+a + a+c − σ g a+b c+ + c−b+a , ( ) 1 1 2 2 3 3 1 . . n D j j j j H χ a+ χ b+ χ c+ c c = =Σ Γ + Γ + Γ + where a (a+ ), b(b+ ), c (c+ ) are the annihilation (creation) operators of excitons, biexcitons and photons, respectively. ω is the frequency of cavity mode. 1 ω and 2 ω are the energy of exciton and biexciton creation, respectively. g is the constant of photon-exciton interaction. σ is the constant of conversion of excitonilor înto biexcitons. ( ) ( ) ( ) 1 1 2 2 3 3 , , j j j j j j Γ Γ+ Γ Γ+ Γ Γ+ are the operators of anihilation (creation) of reservuars of exciton, biexciton, and photons, respecively. 1 2 3 χ , χ , χ are the constant of coupling between rezervoar and particles. Using the Hamiltonian (1) we obtain the Fokker-Planck equation expresed in terms of complex variables of the field. The later one was transformed into Fokker-Planck equation with amplitude and phase as variables. Niglecting the phase variation, we derived the Fokker-Planck equation for the amplitude of the transmited light. In the stationary case, when performing detailed balance condition, we obtain the stationary solution expressed in terms of potential. A comparison of optical self-organization phenomena within quantum treatment with that of semi-classical model is presented. Finally, the optimum conditions for the manifestation of the phenomena are investigated, and their possible applications are discussed.