The present invention relates to a system and method of transmitting an emergency condition using a wireless sensor network that transmits a user's emergency condition using a wireless sensor network. A wireless sensor network communication device integrated with a biological sensor is attached to a user's body in order to gather user's biological information, and transmits the user's biological information through the wireless sensor network. A repeater receives the biological information from the communication device, and sends the received biological information by using a routing protocol of the wireless sensor network. A management server receives the biological information through the repeater, analyzes the biological information, and transmits a warning signal to a user or takes emergency measures. Therefore, it is possible to detect and cope with sudden physical problems, which are generated during user's exercises and outdoor activities, at an early stage. As a result, it is possible to significantly contribute to the prevention and reduction of danger for the weak and the elderly, and a user who is to be taken care of.