Under the renewal system for the plants varieties protection,the plant variety renewal decisions determine the maintenance time and reflect the quality of the plant variety rights to provide a solid basis for decision-making to improve the plant variety protection and maintenance system. Based on the data from the Office for the Protection of New Plant Varieties,the Ministry of Agriculture of China on the application,authorization and variety rights announcement from 1997 to 2017,this paper uses Kaplan-Meie...