To easily predict a new biological/functional activity unknown yet such as a decarboxylation activity of prion protein and a β-amyloid protein precursor to oxaloacetate and a biological activity analogous to calcitonin and human growth hormone.

An EIIP index number is given to amino acid (or nucleic acid) in an amino acid sequence area existing in the complete amino acid sequence of an optional protein and containing a known motif related to an active site, and a frequency spectrum obtained by discrete Fourier transformation of an obtained number sequence (EIIP sequence) and a frequency obtained by discrete Fourier transformation of the EIIP sequence of the complete amino acid sequence are found. Subsequently, a specific frequency value derived from the active site of the protein is selected from a total amino acid frequency spectrum obtained by crossing these spectra, an approximate value of the specific frequency is retrieved, and consequently, a biological/functional activity of the optional protein is predicted.