Implementation of this invention provides a method of chatting. The method including: access to information input language, the language of the information backbone and determination of sentence patterns through the topic: Preferences, the sentence referred to ascertain the trunk and sentence language information topic attributes corresponding to the existence of the sentence referred to the sentence trunk and sentence patterns. If the response from the default, select a topic and attribute the corresponding period of respondents feedback, determine if it is a model from the the correspondingresponse mode, select a feedback. corresponds to the method. The invention also provides a chat system, which include: access modules, natural language processing modules, memory modules of language knowledge, understanding topic modules topic: storage units, reasoning module, reasoning knowledge storage unit send unit.