We obtained a magnetic resonance image of 1 mum resolution and 75 mum(3) voxel volume for a phantom filled with hydrocarbon oil within an hour at 14.1 T. For this work, a specially designed probe with a high sensitivity RF coil and gradient coils generating over 1000 G/cm was built. The optimal pulse sequence was analyzed in consideration of the bandwidth, diffusion coefficients, and T-1 and T-2 relaxations of the medium. The system was applied to the in vivo imaging of a geranium leaf stem to get the images of 2 mum resolution and 200 mum(3) voxel volume. (C) 2001 Academic Press.