Method and system of building knowledge graph and method and system of conversing news event

A system of building a knowledge graph, comprising:

• a memory storing a main event and a plurality of sub events, with the main event being associated with a plurality of sub events;
• and
• a processing device connected to the memory, wherein the processing device is configured to perform:
• classifying a plurality of news articles to the main event;
• using the main event as a first node of the knowledge graph;
• using the sub events as a plurality of second nodes of the knowledge graph respectively;
• connecting the second nodes to the first node;
• extracting a plurality of event summaries from the news articles respectively according to a template;
• using the event summaries as a plurality of third nodes of the knowledge graph respectively, and connecting each of the third nodes to one of the second nodes according to association between the event summaries and the sub events;
• extracting a plurality of commenter identities from the event summaries;
• and
• using the commenter identities as a plurality of fourth nodes of the knowledge graph, and connecting each of the fourth nodes to one of the third nodes.