A karaoke scoring apparatus includes a memory element, a feature extraction element, a similarity measurement element, and a scoring element. The karaoke system includes a reference audio input to be compared with a target audio input for giving a score. The reference audio input and the target audio input are sampled respectively and are transformed sequentially to plural frames of reference sampling signals and plural frames of target sampling signals. The memory element is used for storing the frame of reference sampling signal and the frame of target sampling signal. The feature extraction element is used for performing autocorrelation calculation on the frame of reference sampling signal and the frame of target sampling signal. The similarity measurement element is used for generating a similarity result. The scoring element is used for calculating the similarity results corresponding to the plural frames of sampling signals to output final score.