The invention discloses a communication system and a communication method for assisting a user in acquiring geography-associated information. The communication system comprises a data processing device and a plurality of mobile communication devices. The data processing device receives first request information containing a position item and a time item from a terminal device of the user, and broadcasts second request information to the mobile communication device in an area related to the position item based on the time item. The data processing device receives response message from the mobile communication device receiving the second request information, receives captured audio and/or video data, and transmits position related information to the terminal device based on the response message. The user transmits response information of response position related information to the data processing device through the terminal device. The data processing device transmits the audio and/or video data (representing the geography-associated information) related to the response information to the terminal device.