Abstract-An increasingly important issue in the area of uncertain systems is the estimation of the Robust Domain of Attraction (RDA). Though this topic is of great interest, most of attention has been paid to the RDA for uncertain polynomial systems. This paper considers the RDA for rational polynomial systems and non-polynomial systems, both with parametric uncertainties, which are constrained in a semialgebraic set. The main underlying idea is to reformulate the original system to an uncertain rational polynomial system by using the truncated Taylor expansion and the parameterizable remainder of nonpolynomial functions. A novel way to compute the largest estimate of the RDA is proposed by using a given rational Lyapunov function and the squared matrix representation technique (SMR). Lastly, the benefits of this approach are presented by a numerical example.