A self-learning method for keyword based human machine interaction is disclosed. At least one of a plurality of keywords predetermined in a database is selected and a priority score of the selected keyword is updated and a weighted factor is generated for the selected keyword. A weighted score and the weighted factor of the selected keyword are transmitted to the keywords related to the selected keyword. The selected keyword is pushed to a keyword buffer and linkage strengths between the keywords in the keyword buffer are strengthened. When a keyword has been stored in the keyword buffer for over a predetermined reset time period, a reset operation is performed to remove the keyword from the keyword buffer.