Abstract:The present study was conducted at Dalazi Cave in Ji′an City of southern Jilin Province of China from May 1st 2008 to May 28th 2008. We recorded and analyzed the echolocation calls of Myotis macrodactylus using ultrasound detector (Ultra Sound Gate 116,Avisoft Bioacoustics,Berlin,Germany) and Batsound 3.10 (Pettersson Electronik AB,Sweden),respectively.During flight,M.macrodactylus used short echolocation calls dominated by frequency-modulated (FM) components (1-2 harmonics),with peak frequency of 54.14±3.29 kHz,pulse duration of 3.01±0.60 ms,inter-pulse interval of 62.87±8.89 ms,and the duty cycle of 4.65%±1.12%.Two-tailed t-test analysis of variance indicated significant difference existed in some parameters between echolocation calls produced during flight and hanging,such as the starting frequency of the 1st harmonic,bandwidth and inter-pulse interval.Except the dominant frequency,terminal frequency of 1st harmonic,bandwidth,pulse duration and inter-pulse interval during flight were significantly different between females and males.Different characteristics of echolocation calls in M.macrodactylus at different status might result from their adaptation to foraging strategies,habitats and communication.