It is proved clearly by using H-H COSY that there is the three-substitutedbond in the end of polycyclic sequences of cyclized cis-l

4 polybutadiene．On the other hand

a little of trans-l

4 and l

2-units of polybutadiene are comprised in the residue linear chain of cyclized cisl-

4 polybutadiene as shown in its 13C NMRspectrum Based on information provided by H-H COSY

assignment of thehigh-resolution 1H NMR spectrum of cyclized cis-l

4 polybutadiene is obtainedfinally．In order to get the degree of cyclization(X)and the cyclicity(Y) of cyclizedcis-1

4 polybutadiene two parameters P and Q are defined．In the same time．the relationship between X

Y and P

Q are discussed and the fortnulas calculated X and Y are provided．The method proposed in this paper is satisfactory to investigation of its microstructure and physical

physical-chemical properties．