Electronic Journal of Differential Equations, Vol. 2020 (2020), No. 106, pp. 1-26. Title: Exponential decay and blow-up for nonlinear heat equations with viscoelastic terms and Robin-Dirichlet conditions Authors: Le Thi Phuong Ngoc (Univ. of Khanh Hoa, Ho Chi Minh City, Vietnam) Nguyen Thanh Long (Univ. of Science, Ho Chi Minh City, Vietnam) Abstract: In this article, we consider a system of nonlinear heat equations with viscoelastic terms and Robin-Dirichlet conditions. First, we prove existence and uniqueness of a weak solution. Next, we prove a blow up result of weak solutions with negative initial energy. Also, we give a sufficient condition that guarantees the existence and exponential decay of global weak solutions. The main tools are the Faedo-Galerkin method, a Lyapunov functional, and a suitable energy functional. Submitted November 20, 2019. Published October 26, 2020. Math Subject Classifications: 34B60, 35K55, 35Q72, 80A30. Key Words: Nonlinear heat equations; blow up; exponential decay.