A new peak at 39.0 ppm in the 13C-NMR spectrum of polybutadiene (PBD) was discovered. This peak is assigned to the fouth trans peak (T4) of trans 1

4-sequence marked with an asterisk as shown in Fig. 3 in the text.The occurrence of T4 carbon nuclei is strongly affected by their neighboring 1

2-units. So long as both contents of trans 1

4- and 1

2-units reach their proper amount

the peak (T4) will appear in the 13C-NME spectrum of PBD.