Abstract: In order to investigate characteristics of noise system,especially moving object underwater,the sound image of measured system had been constructed,using Fresnel integral to Perform the necessary space transformation of sound field.The selection of parameters in Fresnel integral and method of scanning in measurements are discussed in detail.It is also discussed how to calculate Fresnel integral with Fourier transformation.Three experiments are described in the paper,i.e.the sound image of cross array with five elements,the sound image of underwater engine,and the sound image of moving ship model.It had been shown that the position of main sources can be easily determined from the sound images of investigated objects.