wsing the two-dimensional (2D) refocused CP-INADEQUATE spectra of natural abundance Cladophora and tunicate celluloses, we determined the C-13 homonuclear through-bond correlations of cellulose I (alpha) and I-beta, respectively. Two sets of the C-13-C-13 connectivities from C1 through C6 were observed in the 2D INADEQUATE spectrum of the respective cellulose where two directly bonded carbons share the common frequency in the double quantum dimension, which indicated that both cellulose I-alpha and I-beta contain two magnetically nonequivalent anhydroglucose residues in the unit cells. After the C-13 assignment of each carbon of the cellulose I-alpha and i(beta) assignments of the H-1 chemical shifts of protons attached to each carbon of the both allomorphs were performed by use of the 2D MAS-J-HMQC spectra of the cellulose samples for the first time. These spectra gave the through-bond C-13-H-1 correlations, which allowed the assignment of the H-1 chemical shifts of protons that bind to C1, C3, C4, and C6 of the cellulose I-alpha and I-beta. From the differences in the C-13 and H-1 shifts of cellulose L, and It, it was revealed that the primary difference between two forms of cellulose 1 was in the conformations of anhydroglucose residues contained in the cellulose chains. In addition, the conformational difference in the torsion angle around the beta-1,4 linkage between cellulose I-alpha and I-beta was suggested by the notable differences in their H-1 chemical shifts of protons attached to C1.