Abstract: Up to now,only an expression of the on-axis radiation of parametric array can be given from the theory of the pulse self-democlulation.As for the off-axis field,the solution can only be given in an integral form,and merely numerical results are obtained by using the computer,this paper shows that these integrals can be analytically determined almost for all typical primary waves by means of Fourier's convolution theorem which transforms the integrals depending on frequency into time dependent ones.