Electronic Journal of Differential Equations, Vol. 2020 (2020), No. 68, pp. 1-25 Title: Monotone iterative method for retarded evolution equations involving nonlocal and impulsive conditions Authors: Xuping Zhang (Northwest Normal Univ., Lanzhou, China) Pengyu Chen (Northwest Normal Univ., Lanzhou, China) Yongxiang Li (Northwest Normal Univ., Lanzhou, China) Abstract: In this article, we apply the perturbation technique and monotone iterative method in the presence of the lower and the upper solutions to discuss the existence of the minimal and maximal mild solutions to the retarded evolution equations involving nonlocal and impulsive conditions in an ordered Banach space X $$\displaylines{ u'(t)+Au(t)= f(t,u(t),u_t),\quad t\in [0,a],\; t\neq t_k,\cr u(t_k^+)=u(t_k^-)+I_k(u(t_k)),\quad k=1,2,\dots ,m,\cr u(s)=g(u)(s)+\varphi(s),\quad s\in [-r,0], }$$ where $A:D(A)\subset X\to X$ is a closed linear operator and -A generates a strongly continuous semigroup T(t) $(t\geq 0)$ on X, a, r>0 are two constants, $f:[0,a]\times X\times C_0\to X$ is Caratheodory continuous, $0