A data analysis system includes relay apparatuses for communicating with a wireless terminal in a communication area of the relay apparatus, and a data analysis apparatus connected to the relay apparatuses through a communication network for analyzing data regarding the wireless terminal, wherein each relay apparatus includes a determiner for determining whether the wireless terminal is present in the communication area at fixed time intervals, a time imparter for imparting a time at which the determination is performed to a determination result, and a transmitter and receptor for transmitting the determination result to the data analysis apparatus with the imparted time, and the data analysis apparatus includes a transmitter and receptor for receiving the determination result and the imparted time, an analyzer for analyzing information on the wireless terminal at each time based on the time and the determination result, and a display for displaying an analysis result.