A device for detecting occurrence of wheeze in a lung sound includes an acoustic processing unit, a filtering unit, and an identifying unit. The acoustic processing unit is for obtaining a lung sound and for generating a raw sound signal accordingly. The filtering unit is for filtering the raw sound signal to obtain a filtered signal. The filtered signal has a plurality of sections with respect to the time domain. The identifying unit is for computing an energy value of each of the sections of the filtered signal, and for determining that a wheeze occurs when the energy values of a part of the sections are larger than a predetermined value and duration of the part of the sections is longer than a predetermined observation time.
