The C-13 CP/MAS(cross polarization/magic angle spinning) NMR spectrum of solid poly(gamma-benzyl L-glutamate) (PBLG) was measured at the slow spinning rate of 1.9 kHz. The exact principal values of the C-13 chemical shift tensor (delta(11), delta(22), and delta(33)) for the main-chain carbonyl carbons of PBLG were obtained from an intensity analysis of the spinning sidebands, according to Hertzfeld-Berger method. Further, the C-13 CP/MAS NMR spectra and static C-13 CP NMR of PBLG were measured in a liquid crystalline solution, where PBLG takes the alpha-helix form. The experimental results show that there exists a linear relationship between the order parameter S and the observed main-chain carbonyl C-13 chemical shift, delta(obs), such as S = 0.024 x delta(obs) - 3.758. Using the delta(obs) value and the S-delta(obs) relation, the order parameter S of PBLG in the liquid crystalline state was determined to be 0.875 +/- 0.025. The delta(obs) value was then used as a monitor for determining the degree of orientation of PBLG in the PBLG gel. Furthermore, the diffusional behavior of 1,4-dioxane as solvent in the PBLG liquid crystalline solution, and in the highly oriented PBLG gel prepared in the magnetic field, was elucidated by the pulsed-field gradient spin-echo H-1 NMR method.