With the current attention on ecological and environmental protection, regulations on environmental protection and extended producers responsibilities, more and more manufacturers are introducing reverse logistics (RL) into their forward supply chain (SC). RL together with forward logistics consists of a closed-loop supply chain (CLSC). This research aims to establish a systematic understanding of RL systems with a focus on product returns and their impacts on CLSC operations. In order to do so, the research is developed from both theoretical and practical angles. In terms of theoretical understanding, the research studies up-to-date literature regarding RL and CLSC, and identifies criteria affecting RL and CLSC operations specifically in product returns. Then, the mathematical models are developed based on practical RL and CLSC operations including examining existing regulations and their impact on customer product return behaviour, mapping RL operations and forecasting product returns, and exploring the CLSC dynamic performance. The research contributes to both current study on RL/CLSC and practitioners within the relevant areas as: (1) it explores various RL options and their practices in a CLSC system through a comprehensive literature review, which builds a foundation for mapping RL operational processes, developing mathematical models in understanding the impact of legislation on RL, forecasting product returns, and exploring CLSC dynamic performance; (2) it quantifies relationships between legislative enforcement, green awareness and product returns over a product life cycle; (3) it advances a generic Graphical Evaluation and Review Technique model with a control theory method, i.e. Mason's rules to forecast multi-level product returns; (4) it develops a SD model to examine how product returns affect the CLSC's product order rate and its inventory level, both are directly related to cost.