The latest research progress in audio forensics is introduced with the emphasis on audio authenticity. First, the history of audio forensics research is reviewed. The classification of audio forensics is discussed. Then, the framework of audio forensics is designed. Several key technologies of audio forensics are summarized including audio active forensics technology,audio tamper technology based on electrical network frequency (ENF),audio tamper detection technology with different sampling rates and audio tamper detection technology with the same sampling rates under the passive power grid frequency components,the characteristic parameters of recording equipment,pattern recognition ,situation of database construction , recording environment identification and so on.Finally,the prospective of audio forensics technology is presented.