To provide a data communication system and communication method that can balance profit between a contents provider and users.

The data communication system and communication method are provided with a contents providing terminal 10, that transmits music data and music data provider identification data, a server device 20 that receives and stores the music data and the music data provider identification data, and a mobile communication terminal 30 that transmits user identification data to the server unit 20, receives and stores the music data distributed from the server device 20 on the basis of the user identification data, and reproduces the music data, when receiving a call. When the server device 20 receives music data from the contents providing terminal 10, the server device 20 increases account data of a provider of the music data; and when the server device 20 transmits the music data to the mobile communication terminal 30, the server device 20 decreases account data of the mobile communication terminal 30 to balance the profit of the both.