from the perspective of the construction and improvement of data asset trading mechanism，this paper proposes that determining the rights of data assets is the premise of promoting the cultivation of data factor market and the effective flow of data assets. Data assets right includes ownership，researching right and use right，providing the method of data asset ownership definition，transaction and process；According to the participants’ intellectual labor and economic resources input，this paper puts forward the basis for the establishment of data asset interests distribution mechanism in each node of the big data value chain，which is also the key to further promote data sharing and cultivating the data assets trading market；Based on the blockchain technology，this paper establishes the data asset right determination and transaction process according to the characteristics of blockchain，and intends the raw data，data product right determination and transaction mechanism.