This system consists of the transmission with 40g weigh and 195-220kHz band, 45 multiple antennas, receiver(selection level meter) and microcomputer for finding the location of hares. We got 38 data through 40 times experiments between 5:56 p.m. and 6:46 p.m. on October 8, 1984 in Niigata University Forest, Muramatsu Nursery. It took 82 seconds to obtain one datum of finding the location of two hares at the same time, which took 3 times as much as tracing single hare's behaviour. We expect that we can get the data of mutural relationship between two hare through this observation.