In recent years, mobile ad hoc networks (MANETs) have become popular in different areas. In MANETs, mobile nodes can join or leave the network freely. Because of the mobility of nodes and open wireless medium, MANETs are vulnerable to security attacks. In this thesis, we propose a novel framework of software-defined MANETs with trust management. Specifically, we separate the forwarding plane in MANETs from the control plane, which is responsible for the control functionality, such as routing protocols and trust management in MANETs. Using the on-demand distance vector routing (TAODV) protocol as an example, we present a routing protocol named software-defined trust based ad hoc on-demand distance vector routing (SD-TAODV). Simulation results are presented to show the effectiveness of the proposed softwaredefined MANETs with trust management. iii First of all, I would like to sincerely thank my supervisor, Professor F. Richard Yu for his tremendous time and efforts spent in leading, supporting and encouraging me in the course of my thesis and study. It would not be able for me to finish my thesis without his help and I will always keep to follow his instructions and inspiration to my professional career. I would also thank my colleagues for their understanding and friendship during the time we spent together. Finally, I would like to express my special thanks to my parents for their continuous understanding, supporting and encouraging in my life. v