The robustness of fuel control system for boilers has been discussed.Based on analysing the features of controlled object for fuel

it is simplified as a second-order inertia object.In order to consider uncertainty of the system

the model of controlled object has been expresed by using T-S fuzzy model

and a controller being designed.A positive definite symetrical matrix has been obtained by solving the Ricicati Inequality

thereby the secondary stability of closed loop for the fuzzy system being decided

and being verified by the phase-plane diagram.Results show that this fuel control system has strong robustness;compared with traditional control

the time duration of regulation is short

dynamic deviation being small

without static deviation

and the quality of control being better.