Since many process control designs suffer degradation or failure from systems with input constraints and/or complex dynamic behavior, the control objective is to stabilize reactor systems which have constraints on both the magnitude and the rate of change of manipulated input. The developed constrained control schemes are composed of a nonlinear feedback for achieving the satisfactory tracking performance combined with a high-gain control to impair other possible large controller motions. On the basis of this two-input control scheme, the closed-loop stability can be guaranteed, and the bounded output regulation can also be achieved. Within the stable observation framework; the saturated output feedback control is developed. Finally, the proposed four designs are all evaluated through the simulations of the control of a nonisothermal CSTR with chaotic behavior.