**Background and Objective:**Recently, the linear quadratic (LQ) optimization subject to descriptor system received much attention from several researchers in field of descriptor system. In this study, it was aimed to establish a sufficient condition that guaranteeing the existence of pair the optimal control and optimal state of the LQ optimization problem subject to descriptor system under disturbance.

**Materials and Methods:**In order to solve the considered problem, the LQ optimization problem subject to descriptor system transformed into the normal LQ optimization problem. The available results of the normal LQ optimization problem were utilized to find a sufficient condition for the existence of optimal solution for LQ optimization problem subject to descriptor system under disturbance.

**Results:**The final results show that this sufficient condition constitutes a method to find the pair the optimal control and optimal state of the LQ optimization problem subject to descriptor system under disturbance.

**Conclusion:**The impulse controllability and stabilizability of the constraint constitute the desired sufficient condition.]]>