An integrated scheme for parameter optimization of MR dampers used in the semiactive stochastic optimal control of structures subjected to random seismic ground motion is provided in this paper. This scheme involves a simultaneous optimization of the weighting matrices pertaining to optimal active control and the damping coefficient, the maximum Coulomb force pertaining to optimal semiactive control, so as to attain a similar consistent control gain between the two control modalities. As a probabilistic measure with practical meanings, reliability is considered as the argument linked with the control criterion for the parameter optimization. In order to reveal the applicability of the integrated scheme, the semiactive stochastic optimal control of a SDOF system representing one-story shear-type frame structures is carried out. Advantages of the integrated scheme are addressed in comparison with the control gain of the MR damper optimized by the previously proposed separated schemes. It is shown that both the integrated and separated schemes can achieve an excellent control effectiveness, where the root-mean-square time histories and probability density function distribution of structural displacement and acceleration are reduced significantly, indicating that a more safe and more comfortable structural system is obtained. However, the integrated scheme attains a more serious displacement and a similar acceleration control, but pays a slightly larger MR damper force than the separated scheme, which allows for a better trade-off between control effectiveness and control cost.