1. A system for recognizing physiological sound, comprising: a receiving module configured to receive a physiological sound; a feature extracting module configured to extract at least one feature from the physiological sound; and a classifier configured to classify the at least one feature to identify at least one category; wherein the feature extracting module comprises a voice activity detector (VAD) module configured to detect at least one segment from the physiological sound, a Mel-frequency cepstrum coefficients (MFCC) module configured to transfer the at least one segment to at least one MFCC feature vector, and a K-means algorithm module configured to find at least one representative data point from the at least one MFCC feature vector.