Abstract: Three modes of the Tunneling Acoustic Microscopy (TAM),tip sample force interaction mode,improved STM mode and improved AFM mode,are investigated in this paper.Their mechanisms are studied.By setting up a tip-sample interaction model,the relation of the interaction forces with tunneling gap is analysed.The theoretical calculations are in agreement with the experimental data.The results are valuable and important for developing the TAM Experimental system and preparing the tips.