Nuclear-magnetic resonance spectrometry is a method of analysis which has been widely applied not only in the field of science and engineering but also in medicine. In using nuclear-magnetic resonance method in the field of cultural property studies, there are several points which must be taken into consideration due to the characteristics of the ways of measurement. In this study an attempt was made to calculate the ratio of the prescence of -helix and -sheet structures in a silk fibre be detecting their ratio based on the difference in intensity of their chemical shift value of 13C by NMR. As a result, it is assumed that this ratio has been influenced by changes in climate.