Abstract: During the period of railway transportation, the liability determination of the passenger injury cases caused by the third party becomes the focus of dispute. The types of passenger damages caused by the third party's liability was discussed firstly. Then, according to the constitutive requirements of liability for breach of contract and liability for tort in ″contract law″ and ″tort liability law″, by analyzing the causes of passenger damage, the subject of the third party's liability was clarified in combination with the provisions of relevant laws. The law applicability of joint liability for tort undertaken by railway enterprises, supplementary liability for compensation, prepayment obligation, security obligation and other aspects were also analyzed, and the responsibilities of all parties were clarified to promote the legal and reasonable handling of passenger injury cases, the establishment of a good railway passenger transport order, and the social harmony and stability. The research results show that: passengers can ask railway companies for undertaking the liability for breach of contract, and ask the third party to undertake tort liability. Only when the third party is not clear or without ability to pay compensation, will the railway company assume supplementary liability. After the railway pays compensation in advance, the third party can be pursued. In order to make up for the loss of railway company caused by law gaps, the insufficient part of compensation can be solved by insurance.

Key words: third person, railway, passengers, casualties, law, responsibility