The present invention relates to a communication system, a communication method, an information processing apparatus, and an information processing method for easily and quickly organizing a communication group containing a plurality of apparatuses. The user places a PDA 2 in proximity to a personal computer 1. When an electromagnetic wave emitted from a reader/writer of the PDA 2 is received by a reader/writer of the personal computer 1, the personal computer 1 notifies the PDA 2 of stored communication group organizing information. The PDA 2 stores the communication group organizing information while establishing a synchronization for a Bluetooth communication with the personal computer 1 based on the communication group organizing information to establish the Bluetooth communication with the personal computer 1. The present invention is applicable to a variety of information processing apparatuses such as a personal computer and a PDA.