Abstract: Whether artificial intelligence（AI）can enjoy the status of legal subject is the root of solving the realistic problem of ascribing the subject of liability for AI tort liability. From the angle of legal philosophy， the paper creatively constructs the hierarchical standard system of a legal subject and its contingent conditions，and then puts forward the hierarchical judgment system of entrusting the legal subject status. From the abstract to the concrete，the problem of ascribing the subject of liability for AI tort liability is studied by using this system as the judgment standard. Since weak artificial intelligence cannot become a legal subject，the idea of legal status representative is put forward on the basis of the compulsory insurance mechanism of the production side. Strong artificial intelligence，according to the different sources of its self-consciousness，is divided into“machine ethics”and“human emotion.”The former cannot become a legal subject，but the human-designed“machine ethics”can effectively reduce the probability of damaging events，and therefore，the idea of legal status representative still works；the latter should not become a legal subject，for otherwise，it will not satisfy the value judgment，or even relevant discussion will be meaningless. Under the premise that artificial intelligence is not regarded as a legal subject，and based on China’s current law and motor vehicle liability insurance mechanism，the ascription of the subject of liability for AI tort liability is clearly defined from theory to practice，drawing on foreign legislative experience and cases. It helps to improve the scheme of ascribing the subject of liability for AI tort liability in the field of automatic driving with Chinese characteristics.

Key words: AI infringement, automatic driving, subject of liability, hierarchical system, machine ethics