Abstract: To gain a deeper understanding on odontocetes click and develop smart protection strategy for endangered species,clicks of Indo-pacific humpback dolphins(Sousa chinensis) and finless porpoises(Neophocaena asiaeorientalis sunmeri) were recorded and analyzed.Passive acoustic monitoring was used to record the clicks emitted by Indo-Pacific humpback dolphins and finless porpoises during boat-based field surveys in the Xiamen waters.Subsequent analysis shows:clicks emitted by Indo-Pacific humpback dolphins are characterized by short duration,high frequency,and broadband bandwidth.Comparatively,finless porpoise' clicks have a relatively longer duration,higher peak frequency,and narrower bandwidth.Duration,centroid frequency and-10 dB bandwidth of clicks are significantly different between the two species.