Abstract: At present, theorists have not reached a consensus on the rights of the the No286 article of Contract Law In order to explore the nature of the right, by adopting comparative analysis, this article is analyzed from  legislation and constitution of actual rights angle, and it is concluded that the right belongs to mechanic′s lien Meanwhile, the establishment of mortgage right and the order of repayment of contractor are analyzed, and it is pointed out that the mortgage of contractor has priority position because the right belongs to the expense lien, neither lien in the law of real right nor theoretical priority

Key words: mechanic′s lien, expense lien, lien, priority