Abstract: To study the factors affecting ultrasonic amplitude imaging of porous silicon oxide nano-films based on atomic force acoustic microscopy (AFAM) technology. The AFAM system was built, the silicon oxide and porous silicon oxide nano-films were detected, and the first two order contact resonance frequency and ultrasonic amplitude images were obtained. The influence of the parameters including excitation frequency and scanning frequency in the process of test on the stability and the influence of ultrasonic excitation on nano-friction were analyzed. Results show that the ultrasonic amplitude images are affected by excitation frequency and the ultrasonic excitation can reduce the friction in the scanning process.