Based on the collection of the relevant literatures of water right trading around the world, the current research results and problems are summarized. The current research results and future research trends are reviewed from the aspects of the definitions of water right and water right trading, premise, pricing, external effect and government. The analysis of the literatures shows that the successful cases and experience of the latest few decades have resulted in a relatively complete research system for this matter, but it's still not ideal in some perspectives such as connotation of water right, premise of water right trading and pricing of water right. Thus, it is suggested that the connotations of water right and water right trading, the efficiency evaluation of water right trading process and the effects of ecological environment should be further studied.