From 2005 to 2009, we collected the samples of Myotis davidii’s echolocation calls, wing shape and faecal pellets, and analyzed the echolocation calls, wing shape and summer diet of an endemic Chinese bat, M.davidii. The results indicated that the peak frequency, bandwidth and duty cycle of echolocation calls is 60.4±10.0 kHz (Mean±SD), 54.7±8.5 kHz and 7.4%±3.5%, respectively. Aspect ratio, wing loading and tip shape index is 6.2±0.8, 5.3±0.9 N/m² and 2.2±0.8, respectively. The summer diet of M.davidii is mainly consisted of the insects of Coleoptera (57.7%, volume percent) and Diptera (36.0%) insects from fecal analysis. Based on the analysis of echolocation calls, wing shape and summer diet, we speculate that M.davidii mainly probably forages in complex forest habitat.