The sensor node communication terminal (20) capable of executing power saving communication and the wireless sensor network system to which such sensor node communication terminals (20) can be applied, the sensor node communication terminal includes: a sensor (21) capable of collect sensor information at an installed location in autonomous timing； a control unit (24) connected to the sensor (21) and capable of executing calculation processing of the sensor information； a memory (22) connected to the control unit (24)； a wireless transmission/reception unit (26) connected to the control unit (24)； an antenna (28) connected to the wireless transmission/reception unit (26) and capable of wirelessly transmitting the sensor information or a result of the calculation processing of the sensor information； a power supply unit (32) connected to the control unit (24)； and a timer (30) connected to the control unit (24), wherein second wireless transmission data can be received from a host side during only a predetermined time period after transmission of wireless transmission data is completed. There can be provided the communication terminal and the wireless sensor network system can execute power saving communication.
