<p style='text-indent:20px;'>In this paper, we give a general decay rate for a quasilinear parabolic viscoelatic system under a general assumption on the relaxation functions satisfying <inline-formula><tex-math id="M1">\begin{document}$ g'(t) \leq - \xi(t) H(g(t)) $\end{document}</tex-math></inline-formula>, where <inline-formula><tex-math id="M2">\begin{document}$ H $\end{document}</tex-math></inline-formula> is an increasing, convex function and <inline-formula><tex-math id="M3">\begin{document}$ \xi $\end{document}</tex-math></inline-formula> is a nonincreasing function. Precisely, we establish a general and optimal decay result for a large class of relaxation functions which improves and generalizes several stability results in the literature. In particular, our result extends an earlier one in the literature, namely, the case of the polynomial rates when <inline-formula><tex-math id="M4">\begin{document}$ H(t) = t^p, \ t\geq 0, \forall p>1 $\end{document}</tex-math></inline-formula>, instead the parameter <inline-formula><tex-math id="M5">\begin{document}$ p \in [1, \frac{3}{2}[ $\end{document}</tex-math></inline-formula>.</p>