Abstract: Coupling adjacent tall buildings with supplemental control devices is a practical and effective approach to mitigating structural seismic response. In this paper, a stochastic optimal control method for coupled adjacent tall building structures is presented based on the stochastic dynamical programming principle and the stochastic averaging method. A reduced-order model of coupled structures with an arbitrary number of stories and with connecting control devices at any floors is formulated. Then the stochastic averaging method is applied to the coupled structures to yield oIt stochastic differential equations for modal energies. The stochastic dynamical programming principle is applied to the energy processes to establish a dynamical programming equation, from which an optimal control law is determined. The structural response control is performed by the modal energy control and the dimension of control system is reduced. The seismic excitation is modeled as a Gaussian random process and the power spectrum can be taken into account. Numerical results illustrate the effectiveness and efficiency of the proposed stochastic optimal control method for coupled structures.