Abstract: A method of transmitting and receiving data for a wireless sensor network system is disclosed. Transmission and reception intervals for a small amount of data and for a large amount of data are set. A sensor node checks data requested to be transmitted. If the data is a small amount of data, the sensor node transmits the data to a higher or lower communication node during the transmission interval for a small amount of data. If the data is a large amount of data, the sensor node divides the large amount of data and then transmitting resulting data to the higher or lower communication node during the transmission interval for a large amount of data. The sensor node receives the small amount of data during the reception interval for a small amount of data and the large amount of data during the reception interval for a large amount of data.