Abstract: Extraction and interpolation of signal is necessary to be performed for changing the sampling rate of signal.When the rate of interpolation is high,the calculation becomes burdensome and hard to be implemented with hardware.An algorithm for reducing the computation is proposed.Based on analyzing the relationship between the input signal,output signal and filter coefficients and combining with the rate of sampling rate changing the algorithm performs multiply-accumulate operation to the points needed.Experiments show that sampling rate changing can be implemented with great reduction of computation load by this method.