The structural effects on the defective formation and the crystal mor-phology in the crystal of urea have been studied. The face development is discussedfrom the viewpoint of the molecular resonance structures and defects, and the form oflarge strained fields is also discussed from the existence of the structural channels alongthe c-axis. The structural effects on the defective formation and the crystal mor-phology in the crystal of urea have been studied. The face development is discussedfrom the viewpoint of the molecular resonance structures and defects, and the form of large strained fields is also discussed from the existence of the structural channels along the c-axis.