With many significant advantages over commercial profits,open source computer-aided translation(CAT)tools are widely used in open source community.However,Chinese translation scholars have rarely set foot on open source CAT research.Given such a background,the paper first discusses the concept of open source CAT tools,then illustrates the main tools and their applications in translation practice,and analyzes the pros and cons as well as the development trends of open source CAT tools.Finally,the paper holds that the open source CAT technology will play an increasingly important role in the practice and teaching of translation.