A method, performed by an electronic device, of generating summary information of a conversation text, includes: obtaining at least one first summary text extracted from at least one conversation text of a previous conversation; extracting at least one second summary text from a conversation text of a current conversation; identifying, from among the at least one first summary text, a summary text having a same type as a type of the at least one second summary text; adjusting a score indicating an accuracy of the identified summary text; selecting, from among the at least one first summary text and the at least one second summary text, a summary text corresponding to each of at least one specified type based on a score of each summary text; and generating the summary information based on the selected summary text.