Abstract: Five adult and two young female bats of Rhinolophus pearsoni were captured in Mingu town,Zhenfeng County of Guizhou Province.Their echolocation calls were received with ultrasound detector(D980,ULTRASOUND DETECTOR),read out at one-tenth of the original speed,and then recorded to computer.Batsound 3.10 software was used to analyze the recorded echolocation calls.The result showed that the adult bat emitted FM-CF-FM calls often with 2-3 harmonics,the calls dominant frequency,pulse duration and interpulse interval were 56.80±0.62 kHz,34.62±5.29 ms and 86.50±19.72 ms at fly,and 58.05±0.24 kHz,41.08±5.87 ms and 117.29±66.44 ms at hang,respectively,and duty cycle was (44.06±12.58)% at fly and (46.00±24.25)% at hang.The young bat emitted CF-FM calls with 5-8 harmonics.The calls dominant frequency of the young was lower,FM bandwidth was narrower,pulse duration and interpulse interval were shorter,and duty cycle was lower than those of the adult.It is suggested that the echolocation call was correlated with the age in bats R.pearsoni.The adult call responded for detecting the information of food and surroundings,and the young one was for communicating with its mother.