Chemical shift values of ${alpha}$-proton of trans- and cis-methyl cinnamates are well correlated with ${sigma}({sigma}_1,; {{sigma}_R}^{alpha})$, and (F, R) (r=0.999-0.879). It is observed that (1) the degree of variation of ${delta}H_{alpha}$ value by varying the substituents in trans-cinnamates is similar to that of cis-cinnamates <TEX>$({ ho}_{trans}=0.296,;{ ho}_{cis}=0.2840, (2) resonance contribution is larger in the trans-cinnamates than that in the cis-cinnamates, but inductive contribution is reversed, (3) for m-substitued derivatives, resonance contribution is very small compared to that for p-substituted derivatives.