A microcoil probehead for solid-state NMR was developed with a two-channel radio-frequency circuit, and C-13 observation with a proton-decoupling probehead was performed to obtain information on the distribution of the orientation of silk fibroin molecules in the fiber. The coil (1 mm (diameter) x 5 mm (length)) of the probehead was placed at the angles 90 degrees and 30 degrees, relative to the static magnetic field. Only 70 mu g of [1-C-13]-Gly silk fibroin fiber was used in a magnet of 9.4 T (400 MHz for proton channel).