This study aims to see the form of responsibility of PT Kereta Api Indonesia (Persero) in the event of loss of passenger luggage based on the principles of transportation law in Indonesia and legal norms that govern rail traffic. The research method used in this research is normative legal research which is strengthened by interviews with accountable sources. The results of the research that the authors found were that in the event of baggage loss experienced by passengers of PT KAI based on Government Regulation Number 72 of 2009 concerning Railway Traffic and Transportation, PT KAI is not responsible for compensating for lost luggage. PT KAI as the Railways Facility Operator is only responsible for the Passenger Carried in the event of PT KAI's negligence, and the responsibility for the goods transported by freight train. Meanwhile for passenger baggage items, such as baggage items in train cars while traveling, PT. Kereta Api Indonesia (Persero) is not responsible. This is because the missing items are not transported specifically using a carriage or luggage cart (not the passenger's luggage).