At present, the instruments used in non-destructive inspection of pilefoundations in China mainly belong to the time domain, so that the interpre-tation of its results mainly adopts the analytical method of time domain.Nevertheless, the analysis of frequency domain is characterized by directperception through the senses and therefore has its unique merits. Throughdescribing the solution of the wave equation for excitation response of pilefoundation in the frequency domain, this paper makes a rough discussion onthe analytical method for pile foundation quality in the frequency domain.