Abstract: A method, substituent chemical shift (SCS), which is used in assignments of the ¹³C NMR spectra of ethylene-α-olefine copolymers, is proposed in this paper. The SCS method reveals the corresponding relation bctwce the peaks of spectrum of the copolymer and its sequences. At the same time, the relation is elucidated in a systematic way. The ¹³C NMR spectra of the copolymers are firstly divided into two categories according to the above mentioned relation apparent or not. Secondly, three critcrions for classification are suggested:SCS parameters (S₁ and S₂), spectrum of comonomer homopolymer and electrowithdrawing or electrodonating of substituent. Finally, the SCS method is compared with the Grant-Paul method in many ways.

Key words: Substituent chemical shift (SCS) or substituent effect, ¹³C NMR, Ethylene-α-olefine copolymers (ethylene-vinyl substituted copolymers), Sequence structure