Electronic Journal of Differential Equations, Vol. 2024 (2024), No. 35, pp. 1-11. Title: Massera type theorems for abstract non-autonomous evolution equations Authors: Lan-Ling Zheng (Jiangxi Normal Univ., Nanchang, Jiangxi, China) Hui-Sheng Ding (Jiangxi Normal Univ., Nanchang, Jiangxi, China) Abstract: We establish two fixed point theorems for affine maps in Banach spaces, with weaker assumptions than those in the literature. Then we establish some Massera type results for abstract linear evolution equations without assuming the existence of bounded solutions, which is an indispensable condition in the classical Massera theorem and in the earlier literature. As application, we present an existence result on periodic mild solutions to abstract nonautonomous semilinear evolution equations. Submitted October 8, 2023. Published June 06, 2024. Math Subject Classifications: 34C25, 35B10, 34G10, 47D06. Key Words: Massera theorem; affine map; periodic solution; abstract evolution.