Context: Requirements change commonly occurs during the software development lifecycle. Requirements traceability is one of the important techniques to support requirement change management and analysis, ensure quality and keep requirements consistent during development. We find that existing research mentioned various issues and challenges during practicing requirements traceability, and the practitioners show certain obstacles on the subject. Major existing work of the area focuses on requirements traceability processes, frameworks, and techniques to address certain issues accordingly. And we want to focus on and investigate the existing challenges to practice requirements traceability systematically. Method: We investigate the requiremen...